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1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/blkdev.h>
20#include <linux/module.h>
21#include <linux/buffer_head.h>
22#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/highmem.h>
25#include <linux/time.h>
26#include <linux/init.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/backing-dev.h>
30#include <linux/mount.h>
31#include <linux/mpage.h>
32#include <linux/swap.h>
33#include <linux/writeback.h>
34#include <linux/statfs.h>
35#include <linux/compat.h>
36#include <linux/parser.h>
37#include <linux/ctype.h>
38#include <linux/namei.h>
39#include <linux/miscdevice.h>
40#include <linux/magic.h>
41#include <linux/slab.h>
42#include <linux/cleancache.h>
43#include "compat.h"
44#include "delayed-inode.h"
45#include "ctree.h"
46#include "disk-io.h"
47#include "transaction.h"
48#include "btrfs_inode.h"
49#include "ioctl.h"
50#include "print-tree.h"
51#include "xattr.h"
52#include "volumes.h"
53#include "version.h"
54#include "export.h"
55#include "compression.h"
56
57#define CREATE_TRACE_POINTS
58#include <trace/events/btrfs.h>
59
60static const struct super_operations btrfs_super_ops;
61
62static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
63 char nbuf[16])
64{
65 char *errstr = NULL;
66
67 switch (errno) {
68 case -EIO:
69 errstr = "IO failure";
70 break;
71 case -ENOMEM:
72 errstr = "Out of memory";
73 break;
74 case -EROFS:
75 errstr = "Readonly filesystem";
76 break;
77 default:
78 if (nbuf) {
79 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
80 errstr = nbuf;
81 }
82 break;
83 }
84
85 return errstr;
86}
87
88static void __save_error_info(struct btrfs_fs_info *fs_info)
89{
90 /*
91 * today we only save the error info into ram. Long term we'll
92 * also send it down to the disk
93 */
94 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
95}
96
97/* NOTE:
98 * We move write_super stuff at umount in order to avoid deadlock
99 * for umount hold all lock.
100 */
101static void save_error_info(struct btrfs_fs_info *fs_info)
102{
103 __save_error_info(fs_info);
104}
105
106/* btrfs handle error by forcing the filesystem readonly */
107static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
108{
109 struct super_block *sb = fs_info->sb;
110
111 if (sb->s_flags & MS_RDONLY)
112 return;
113
114 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
115 sb->s_flags |= MS_RDONLY;
116 printk(KERN_INFO "btrfs is forced readonly\n");
117 }
118}
119
120/*
121 * __btrfs_std_error decodes expected errors from the caller and
122 * invokes the approciate error response.
123 */
124void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
125 unsigned int line, int errno)
126{
127 struct super_block *sb = fs_info->sb;
128 char nbuf[16];
129 const char *errstr;
130
131 /*
132 * Special case: if the error is EROFS, and we're already
133 * under MS_RDONLY, then it is safe here.
134 */
135 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
136 return;
137
138 errstr = btrfs_decode_error(fs_info, errno, nbuf);
139 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
140 sb->s_id, function, line, errstr);
141 save_error_info(fs_info);
142
143 btrfs_handle_error(fs_info);
144}
145
146static void btrfs_put_super(struct super_block *sb)
147{
148 struct btrfs_root *root = btrfs_sb(sb);
149 int ret;
150
151 ret = close_ctree(root);
152 sb->s_fs_info = NULL;
153
154 (void)ret; /* FIXME: need to fix VFS to return error? */
155}
156
157enum {
158 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
159 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
160 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
161 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
162 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
163 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
164 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
165 Opt_inode_cache, Opt_err,
166};
167
168static match_table_t tokens = {
169 {Opt_degraded, "degraded"},
170 {Opt_subvol, "subvol=%s"},
171 {Opt_subvolid, "subvolid=%d"},
172 {Opt_device, "device=%s"},
173 {Opt_nodatasum, "nodatasum"},
174 {Opt_nodatacow, "nodatacow"},
175 {Opt_nobarrier, "nobarrier"},
176 {Opt_max_inline, "max_inline=%s"},
177 {Opt_alloc_start, "alloc_start=%s"},
178 {Opt_thread_pool, "thread_pool=%d"},
179 {Opt_compress, "compress"},
180 {Opt_compress_type, "compress=%s"},
181 {Opt_compress_force, "compress-force"},
182 {Opt_compress_force_type, "compress-force=%s"},
183 {Opt_ssd, "ssd"},
184 {Opt_ssd_spread, "ssd_spread"},
185 {Opt_nossd, "nossd"},
186 {Opt_noacl, "noacl"},
187 {Opt_notreelog, "notreelog"},
188 {Opt_flushoncommit, "flushoncommit"},
189 {Opt_ratio, "metadata_ratio=%d"},
190 {Opt_discard, "discard"},
191 {Opt_space_cache, "space_cache"},
192 {Opt_clear_cache, "clear_cache"},
193 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
194 {Opt_enospc_debug, "enospc_debug"},
195 {Opt_subvolrootid, "subvolrootid=%d"},
196 {Opt_defrag, "autodefrag"},
197 {Opt_inode_cache, "inode_cache"},
198 {Opt_err, NULL},
199};
200
201/*
202 * Regular mount options parser. Everything that is needed only when
203 * reading in a new superblock is parsed here.
204 */
205int btrfs_parse_options(struct btrfs_root *root, char *options)
206{
207 struct btrfs_fs_info *info = root->fs_info;
208 substring_t args[MAX_OPT_ARGS];
209 char *p, *num, *orig;
210 int intarg;
211 int ret = 0;
212 char *compress_type;
213 bool compress_force = false;
214
215 if (!options)
216 return 0;
217
218 /*
219 * strsep changes the string, duplicate it because parse_options
220 * gets called twice
221 */
222 options = kstrdup(options, GFP_NOFS);
223 if (!options)
224 return -ENOMEM;
225
226 orig = options;
227
228 while ((p = strsep(&options, ",")) != NULL) {
229 int token;
230 if (!*p)
231 continue;
232
233 token = match_token(p, tokens, args);
234 switch (token) {
235 case Opt_degraded:
236 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
237 btrfs_set_opt(info->mount_opt, DEGRADED);
238 break;
239 case Opt_subvol:
240 case Opt_subvolid:
241 case Opt_subvolrootid:
242 case Opt_device:
243 /*
244 * These are parsed by btrfs_parse_early_options
245 * and can be happily ignored here.
246 */
247 break;
248 case Opt_nodatasum:
249 printk(KERN_INFO "btrfs: setting nodatasum\n");
250 btrfs_set_opt(info->mount_opt, NODATASUM);
251 break;
252 case Opt_nodatacow:
253 printk(KERN_INFO "btrfs: setting nodatacow\n");
254 btrfs_set_opt(info->mount_opt, NODATACOW);
255 btrfs_set_opt(info->mount_opt, NODATASUM);
256 break;
257 case Opt_compress_force:
258 case Opt_compress_force_type:
259 compress_force = true;
260 case Opt_compress:
261 case Opt_compress_type:
262 if (token == Opt_compress ||
263 token == Opt_compress_force ||
264 strcmp(args[0].from, "zlib") == 0) {
265 compress_type = "zlib";
266 info->compress_type = BTRFS_COMPRESS_ZLIB;
267 } else if (strcmp(args[0].from, "lzo") == 0) {
268 compress_type = "lzo";
269 info->compress_type = BTRFS_COMPRESS_LZO;
270 } else {
271 ret = -EINVAL;
272 goto out;
273 }
274
275 btrfs_set_opt(info->mount_opt, COMPRESS);
276 if (compress_force) {
277 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
278 pr_info("btrfs: force %s compression\n",
279 compress_type);
280 } else
281 pr_info("btrfs: use %s compression\n",
282 compress_type);
283 break;
284 case Opt_ssd:
285 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
286 btrfs_set_opt(info->mount_opt, SSD);
287 break;
288 case Opt_ssd_spread:
289 printk(KERN_INFO "btrfs: use spread ssd "
290 "allocation scheme\n");
291 btrfs_set_opt(info->mount_opt, SSD);
292 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
293 break;
294 case Opt_nossd:
295 printk(KERN_INFO "btrfs: not using ssd allocation "
296 "scheme\n");
297 btrfs_set_opt(info->mount_opt, NOSSD);
298 btrfs_clear_opt(info->mount_opt, SSD);
299 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
300 break;
301 case Opt_nobarrier:
302 printk(KERN_INFO "btrfs: turning off barriers\n");
303 btrfs_set_opt(info->mount_opt, NOBARRIER);
304 break;
305 case Opt_thread_pool:
306 intarg = 0;
307 match_int(&args[0], &intarg);
308 if (intarg) {
309 info->thread_pool_size = intarg;
310 printk(KERN_INFO "btrfs: thread pool %d\n",
311 info->thread_pool_size);
312 }
313 break;
314 case Opt_max_inline:
315 num = match_strdup(&args[0]);
316 if (num) {
317 info->max_inline = memparse(num, NULL);
318 kfree(num);
319
320 if (info->max_inline) {
321 info->max_inline = max_t(u64,
322 info->max_inline,
323 root->sectorsize);
324 }
325 printk(KERN_INFO "btrfs: max_inline at %llu\n",
326 (unsigned long long)info->max_inline);
327 }
328 break;
329 case Opt_alloc_start:
330 num = match_strdup(&args[0]);
331 if (num) {
332 info->alloc_start = memparse(num, NULL);
333 kfree(num);
334 printk(KERN_INFO
335 "btrfs: allocations start at %llu\n",
336 (unsigned long long)info->alloc_start);
337 }
338 break;
339 case Opt_noacl:
340 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
341 break;
342 case Opt_notreelog:
343 printk(KERN_INFO "btrfs: disabling tree log\n");
344 btrfs_set_opt(info->mount_opt, NOTREELOG);
345 break;
346 case Opt_flushoncommit:
347 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
348 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
349 break;
350 case Opt_ratio:
351 intarg = 0;
352 match_int(&args[0], &intarg);
353 if (intarg) {
354 info->metadata_ratio = intarg;
355 printk(KERN_INFO "btrfs: metadata ratio %d\n",
356 info->metadata_ratio);
357 }
358 break;
359 case Opt_discard:
360 btrfs_set_opt(info->mount_opt, DISCARD);
361 break;
362 case Opt_space_cache:
363 printk(KERN_INFO "btrfs: enabling disk space caching\n");
364 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
365 break;
366 case Opt_inode_cache:
367 printk(KERN_INFO "btrfs: enabling inode map caching\n");
368 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
369 break;
370 case Opt_clear_cache:
371 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
372 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
373 break;
374 case Opt_user_subvol_rm_allowed:
375 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
376 break;
377 case Opt_enospc_debug:
378 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
379 break;
380 case Opt_defrag:
381 printk(KERN_INFO "btrfs: enabling auto defrag");
382 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
383 break;
384 case Opt_err:
385 printk(KERN_INFO "btrfs: unrecognized mount option "
386 "'%s'\n", p);
387 ret = -EINVAL;
388 goto out;
389 default:
390 break;
391 }
392 }
393out:
394 kfree(orig);
395 return ret;
396}
397
398/*
399 * Parse mount options that are required early in the mount process.
400 *
401 * All other options will be parsed on much later in the mount process and
402 * only when we need to allocate a new super block.
403 */
404static int btrfs_parse_early_options(const char *options, fmode_t flags,
405 void *holder, char **subvol_name, u64 *subvol_objectid,
406 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
407{
408 substring_t args[MAX_OPT_ARGS];
409 char *opts, *orig, *p;
410 int error = 0;
411 int intarg;
412
413 if (!options)
414 goto out;
415
416 /*
417 * strsep changes the string, duplicate it because parse_options
418 * gets called twice
419 */
420 opts = kstrdup(options, GFP_KERNEL);
421 if (!opts)
422 return -ENOMEM;
423 orig = opts;
424
425 while ((p = strsep(&opts, ",")) != NULL) {
426 int token;
427 if (!*p)
428 continue;
429
430 token = match_token(p, tokens, args);
431 switch (token) {
432 case Opt_subvol:
433 *subvol_name = match_strdup(&args[0]);
434 break;
435 case Opt_subvolid:
436 intarg = 0;
437 error = match_int(&args[0], &intarg);
438 if (!error) {
439 /* we want the original fs_tree */
440 if (!intarg)
441 *subvol_objectid =
442 BTRFS_FS_TREE_OBJECTID;
443 else
444 *subvol_objectid = intarg;
445 }
446 break;
447 case Opt_subvolrootid:
448 intarg = 0;
449 error = match_int(&args[0], &intarg);
450 if (!error) {
451 /* we want the original fs_tree */
452 if (!intarg)
453 *subvol_rootid =
454 BTRFS_FS_TREE_OBJECTID;
455 else
456 *subvol_rootid = intarg;
457 }
458 break;
459 case Opt_device:
460 error = btrfs_scan_one_device(match_strdup(&args[0]),
461 flags, holder, fs_devices);
462 if (error)
463 goto out_free_opts;
464 break;
465 default:
466 break;
467 }
468 }
469
470 out_free_opts:
471 kfree(orig);
472 out:
473 /*
474 * If no subvolume name is specified we use the default one. Allocate
475 * a copy of the string "." here so that code later in the
476 * mount path doesn't care if it's the default volume or another one.
477 */
478 if (!*subvol_name) {
479 *subvol_name = kstrdup(".", GFP_KERNEL);
480 if (!*subvol_name)
481 return -ENOMEM;
482 }
483 return error;
484}
485
486static struct dentry *get_default_root(struct super_block *sb,
487 u64 subvol_objectid)
488{
489 struct btrfs_root *root = sb->s_fs_info;
490 struct btrfs_root *new_root;
491 struct btrfs_dir_item *di;
492 struct btrfs_path *path;
493 struct btrfs_key location;
494 struct inode *inode;
495 struct dentry *dentry;
496 u64 dir_id;
497 int new = 0;
498
499 /*
500 * We have a specific subvol we want to mount, just setup location and
501 * go look up the root.
502 */
503 if (subvol_objectid) {
504 location.objectid = subvol_objectid;
505 location.type = BTRFS_ROOT_ITEM_KEY;
506 location.offset = (u64)-1;
507 goto find_root;
508 }
509
510 path = btrfs_alloc_path();
511 if (!path)
512 return ERR_PTR(-ENOMEM);
513 path->leave_spinning = 1;
514
515 /*
516 * Find the "default" dir item which points to the root item that we
517 * will mount by default if we haven't been given a specific subvolume
518 * to mount.
519 */
520 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
521 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
522 if (IS_ERR(di)) {
523 btrfs_free_path(path);
524 return ERR_CAST(di);
525 }
526 if (!di) {
527 /*
528 * Ok the default dir item isn't there. This is weird since
529 * it's always been there, but don't freak out, just try and
530 * mount to root most subvolume.
531 */
532 btrfs_free_path(path);
533 dir_id = BTRFS_FIRST_FREE_OBJECTID;
534 new_root = root->fs_info->fs_root;
535 goto setup_root;
536 }
537
538 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
539 btrfs_free_path(path);
540
541find_root:
542 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
543 if (IS_ERR(new_root))
544 return ERR_CAST(new_root);
545
546 if (btrfs_root_refs(&new_root->root_item) == 0)
547 return ERR_PTR(-ENOENT);
548
549 dir_id = btrfs_root_dirid(&new_root->root_item);
550setup_root:
551 location.objectid = dir_id;
552 location.type = BTRFS_INODE_ITEM_KEY;
553 location.offset = 0;
554
555 inode = btrfs_iget(sb, &location, new_root, &new);
556 if (IS_ERR(inode))
557 return ERR_CAST(inode);
558
559 /*
560 * If we're just mounting the root most subvol put the inode and return
561 * a reference to the dentry. We will have already gotten a reference
562 * to the inode in btrfs_fill_super so we're good to go.
563 */
564 if (!new && sb->s_root->d_inode == inode) {
565 iput(inode);
566 return dget(sb->s_root);
567 }
568
569 if (new) {
570 const struct qstr name = { .name = "/", .len = 1 };
571
572 /*
573 * New inode, we need to make the dentry a sibling of s_root so
574 * everything gets cleaned up properly on unmount.
575 */
576 dentry = d_alloc(sb->s_root, &name);
577 if (!dentry) {
578 iput(inode);
579 return ERR_PTR(-ENOMEM);
580 }
581 d_splice_alias(inode, dentry);
582 } else {
583 /*
584 * We found the inode in cache, just find a dentry for it and
585 * put the reference to the inode we just got.
586 */
587 dentry = d_find_alias(inode);
588 iput(inode);
589 }
590
591 return dentry;
592}
593
594static int btrfs_fill_super(struct super_block *sb,
595 struct btrfs_fs_devices *fs_devices,
596 void *data, int silent)
597{
598 struct inode *inode;
599 struct dentry *root_dentry;
600 struct btrfs_root *tree_root;
601 struct btrfs_key key;
602 int err;
603
604 sb->s_maxbytes = MAX_LFS_FILESIZE;
605 sb->s_magic = BTRFS_SUPER_MAGIC;
606 sb->s_op = &btrfs_super_ops;
607 sb->s_d_op = &btrfs_dentry_operations;
608 sb->s_export_op = &btrfs_export_ops;
609 sb->s_xattr = btrfs_xattr_handlers;
610 sb->s_time_gran = 1;
611#ifdef CONFIG_BTRFS_FS_POSIX_ACL
612 sb->s_flags |= MS_POSIXACL;
613#endif
614
615 tree_root = open_ctree(sb, fs_devices, (char *)data);
616
617 if (IS_ERR(tree_root)) {
618 printk("btrfs: open_ctree failed\n");
619 return PTR_ERR(tree_root);
620 }
621 sb->s_fs_info = tree_root;
622
623 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
624 key.type = BTRFS_INODE_ITEM_KEY;
625 key.offset = 0;
626 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
627 if (IS_ERR(inode)) {
628 err = PTR_ERR(inode);
629 goto fail_close;
630 }
631
632 root_dentry = d_alloc_root(inode);
633 if (!root_dentry) {
634 iput(inode);
635 err = -ENOMEM;
636 goto fail_close;
637 }
638
639 sb->s_root = root_dentry;
640
641 save_mount_options(sb, data);
642 cleancache_init_fs(sb);
643 return 0;
644
645fail_close:
646 close_ctree(tree_root);
647 return err;
648}
649
650int btrfs_sync_fs(struct super_block *sb, int wait)
651{
652 struct btrfs_trans_handle *trans;
653 struct btrfs_root *root = btrfs_sb(sb);
654 int ret;
655
656 trace_btrfs_sync_fs(wait);
657
658 if (!wait) {
659 filemap_flush(root->fs_info->btree_inode->i_mapping);
660 return 0;
661 }
662
663 btrfs_start_delalloc_inodes(root, 0);
664 btrfs_wait_ordered_extents(root, 0, 0);
665
666 trans = btrfs_start_transaction(root, 0);
667 if (IS_ERR(trans))
668 return PTR_ERR(trans);
669 ret = btrfs_commit_transaction(trans, root);
670 return ret;
671}
672
673static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
674{
675 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
676 struct btrfs_fs_info *info = root->fs_info;
677 char *compress_type;
678
679 if (btrfs_test_opt(root, DEGRADED))
680 seq_puts(seq, ",degraded");
681 if (btrfs_test_opt(root, NODATASUM))
682 seq_puts(seq, ",nodatasum");
683 if (btrfs_test_opt(root, NODATACOW))
684 seq_puts(seq, ",nodatacow");
685 if (btrfs_test_opt(root, NOBARRIER))
686 seq_puts(seq, ",nobarrier");
687 if (info->max_inline != 8192 * 1024)
688 seq_printf(seq, ",max_inline=%llu",
689 (unsigned long long)info->max_inline);
690 if (info->alloc_start != 0)
691 seq_printf(seq, ",alloc_start=%llu",
692 (unsigned long long)info->alloc_start);
693 if (info->thread_pool_size != min_t(unsigned long,
694 num_online_cpus() + 2, 8))
695 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
696 if (btrfs_test_opt(root, COMPRESS)) {
697 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
698 compress_type = "zlib";
699 else
700 compress_type = "lzo";
701 if (btrfs_test_opt(root, FORCE_COMPRESS))
702 seq_printf(seq, ",compress-force=%s", compress_type);
703 else
704 seq_printf(seq, ",compress=%s", compress_type);
705 }
706 if (btrfs_test_opt(root, NOSSD))
707 seq_puts(seq, ",nossd");
708 if (btrfs_test_opt(root, SSD_SPREAD))
709 seq_puts(seq, ",ssd_spread");
710 else if (btrfs_test_opt(root, SSD))
711 seq_puts(seq, ",ssd");
712 if (btrfs_test_opt(root, NOTREELOG))
713 seq_puts(seq, ",notreelog");
714 if (btrfs_test_opt(root, FLUSHONCOMMIT))
715 seq_puts(seq, ",flushoncommit");
716 if (btrfs_test_opt(root, DISCARD))
717 seq_puts(seq, ",discard");
718 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
719 seq_puts(seq, ",noacl");
720 if (btrfs_test_opt(root, SPACE_CACHE))
721 seq_puts(seq, ",space_cache");
722 if (btrfs_test_opt(root, CLEAR_CACHE))
723 seq_puts(seq, ",clear_cache");
724 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
725 seq_puts(seq, ",user_subvol_rm_allowed");
726 if (btrfs_test_opt(root, ENOSPC_DEBUG))
727 seq_puts(seq, ",enospc_debug");
728 if (btrfs_test_opt(root, AUTO_DEFRAG))
729 seq_puts(seq, ",autodefrag");
730 if (btrfs_test_opt(root, INODE_MAP_CACHE))
731 seq_puts(seq, ",inode_cache");
732 return 0;
733}
734
735static int btrfs_test_super(struct super_block *s, void *data)
736{
737 struct btrfs_root *test_root = data;
738 struct btrfs_root *root = btrfs_sb(s);
739
740 /*
741 * If this super block is going away, return false as it
742 * can't match as an existing super block.
743 */
744 if (!atomic_read(&s->s_active))
745 return 0;
746 return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
747}
748
749static int btrfs_set_super(struct super_block *s, void *data)
750{
751 s->s_fs_info = data;
752
753 return set_anon_super(s, data);
754}
755
756
757/*
758 * Find a superblock for the given device / mount point.
759 *
760 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
761 * for multiple device setup. Make sure to keep it in sync.
762 */
763static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
764 const char *device_name, void *data)
765{
766 struct block_device *bdev = NULL;
767 struct super_block *s;
768 struct dentry *root;
769 struct btrfs_fs_devices *fs_devices = NULL;
770 struct btrfs_root *tree_root = NULL;
771 struct btrfs_fs_info *fs_info = NULL;
772 fmode_t mode = FMODE_READ;
773 char *subvol_name = NULL;
774 u64 subvol_objectid = 0;
775 u64 subvol_rootid = 0;
776 int error = 0;
777
778 if (!(flags & MS_RDONLY))
779 mode |= FMODE_WRITE;
780
781 error = btrfs_parse_early_options(data, mode, fs_type,
782 &subvol_name, &subvol_objectid,
783 &subvol_rootid, &fs_devices);
784 if (error)
785 return ERR_PTR(error);
786
787 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
788 if (error)
789 goto error_free_subvol_name;
790
791 error = btrfs_open_devices(fs_devices, mode, fs_type);
792 if (error)
793 goto error_free_subvol_name;
794
795 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
796 error = -EACCES;
797 goto error_close_devices;
798 }
799
800 /*
801 * Setup a dummy root and fs_info for test/set super. This is because
802 * we don't actually fill this stuff out until open_ctree, but we need
803 * it for searching for existing supers, so this lets us do that and
804 * then open_ctree will properly initialize everything later.
805 */
806 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
807 tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
808 if (!fs_info || !tree_root) {
809 error = -ENOMEM;
810 goto error_close_devices;
811 }
812 fs_info->tree_root = tree_root;
813 fs_info->fs_devices = fs_devices;
814 tree_root->fs_info = fs_info;
815
816 bdev = fs_devices->latest_bdev;
817 s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
818 if (IS_ERR(s))
819 goto error_s;
820
821 if (s->s_root) {
822 if ((flags ^ s->s_flags) & MS_RDONLY) {
823 deactivate_locked_super(s);
824 error = -EBUSY;
825 goto error_close_devices;
826 }
827
828 btrfs_close_devices(fs_devices);
829 kfree(fs_info);
830 kfree(tree_root);
831 } else {
832 char b[BDEVNAME_SIZE];
833
834 s->s_flags = flags | MS_NOSEC;
835 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
836 error = btrfs_fill_super(s, fs_devices, data,
837 flags & MS_SILENT ? 1 : 0);
838 if (error) {
839 deactivate_locked_super(s);
840 goto error_free_subvol_name;
841 }
842
843 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
844 s->s_flags |= MS_ACTIVE;
845 }
846
847 /* if they gave us a subvolume name bind mount into that */
848 if (strcmp(subvol_name, ".")) {
849 struct dentry *new_root;
850
851 root = get_default_root(s, subvol_rootid);
852 if (IS_ERR(root)) {
853 error = PTR_ERR(root);
854 deactivate_locked_super(s);
855 goto error_free_subvol_name;
856 }
857
858 mutex_lock(&root->d_inode->i_mutex);
859 new_root = lookup_one_len(subvol_name, root,
860 strlen(subvol_name));
861 mutex_unlock(&root->d_inode->i_mutex);
862
863 if (IS_ERR(new_root)) {
864 dput(root);
865 deactivate_locked_super(s);
866 error = PTR_ERR(new_root);
867 goto error_free_subvol_name;
868 }
869 if (!new_root->d_inode) {
870 dput(root);
871 dput(new_root);
872 deactivate_locked_super(s);
873 error = -ENXIO;
874 goto error_free_subvol_name;
875 }
876 dput(root);
877 root = new_root;
878 } else {
879 root = get_default_root(s, subvol_objectid);
880 if (IS_ERR(root)) {
881 error = PTR_ERR(root);
882 deactivate_locked_super(s);
883 goto error_free_subvol_name;
884 }
885 }
886
887 kfree(subvol_name);
888 return root;
889
890error_s:
891 error = PTR_ERR(s);
892error_close_devices:
893 btrfs_close_devices(fs_devices);
894 kfree(fs_info);
895 kfree(tree_root);
896error_free_subvol_name:
897 kfree(subvol_name);
898 return ERR_PTR(error);
899}
900
901static int btrfs_remount(struct super_block *sb, int *flags, char *data)
902{
903 struct btrfs_root *root = btrfs_sb(sb);
904 int ret;
905
906 ret = btrfs_parse_options(root, data);
907 if (ret)
908 return -EINVAL;
909
910 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
911 return 0;
912
913 if (*flags & MS_RDONLY) {
914 sb->s_flags |= MS_RDONLY;
915
916 ret = btrfs_commit_super(root);
917 WARN_ON(ret);
918 } else {
919 if (root->fs_info->fs_devices->rw_devices == 0)
920 return -EACCES;
921
922 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
923 return -EINVAL;
924
925 ret = btrfs_cleanup_fs_roots(root->fs_info);
926 WARN_ON(ret);
927
928 /* recover relocation */
929 ret = btrfs_recover_relocation(root);
930 WARN_ON(ret);
931
932 sb->s_flags &= ~MS_RDONLY;
933 }
934
935 return 0;
936}
937
938/* Used to sort the devices by max_avail(descending sort) */
939static int btrfs_cmp_device_free_bytes(const void *dev_info1,
940 const void *dev_info2)
941{
942 if (((struct btrfs_device_info *)dev_info1)->max_avail >
943 ((struct btrfs_device_info *)dev_info2)->max_avail)
944 return -1;
945 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
946 ((struct btrfs_device_info *)dev_info2)->max_avail)
947 return 1;
948 else
949 return 0;
950}
951
952/*
953 * sort the devices by max_avail, in which max free extent size of each device
954 * is stored.(Descending Sort)
955 */
956static inline void btrfs_descending_sort_devices(
957 struct btrfs_device_info *devices,
958 size_t nr_devices)
959{
960 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
961 btrfs_cmp_device_free_bytes, NULL);
962}
963
964/*
965 * The helper to calc the free space on the devices that can be used to store
966 * file data.
967 */
968static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
969{
970 struct btrfs_fs_info *fs_info = root->fs_info;
971 struct btrfs_device_info *devices_info;
972 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
973 struct btrfs_device *device;
974 u64 skip_space;
975 u64 type;
976 u64 avail_space;
977 u64 used_space;
978 u64 min_stripe_size;
979 int min_stripes = 1;
980 int i = 0, nr_devices;
981 int ret;
982
983 nr_devices = fs_info->fs_devices->rw_devices;
984 BUG_ON(!nr_devices);
985
986 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
987 GFP_NOFS);
988 if (!devices_info)
989 return -ENOMEM;
990
991 /* calc min stripe number for data space alloction */
992 type = btrfs_get_alloc_profile(root, 1);
993 if (type & BTRFS_BLOCK_GROUP_RAID0)
994 min_stripes = 2;
995 else if (type & BTRFS_BLOCK_GROUP_RAID1)
996 min_stripes = 2;
997 else if (type & BTRFS_BLOCK_GROUP_RAID10)
998 min_stripes = 4;
999
1000 if (type & BTRFS_BLOCK_GROUP_DUP)
1001 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1002 else
1003 min_stripe_size = BTRFS_STRIPE_LEN;
1004
1005 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
1006 if (!device->in_fs_metadata)
1007 continue;
1008
1009 avail_space = device->total_bytes - device->bytes_used;
1010
1011 /* align with stripe_len */
1012 do_div(avail_space, BTRFS_STRIPE_LEN);
1013 avail_space *= BTRFS_STRIPE_LEN;
1014
1015 /*
1016 * In order to avoid overwritting the superblock on the drive,
1017 * btrfs starts at an offset of at least 1MB when doing chunk
1018 * allocation.
1019 */
1020 skip_space = 1024 * 1024;
1021
1022 /* user can set the offset in fs_info->alloc_start. */
1023 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1024 device->total_bytes)
1025 skip_space = max(fs_info->alloc_start, skip_space);
1026
1027 /*
1028 * btrfs can not use the free space in [0, skip_space - 1],
1029 * we must subtract it from the total. In order to implement
1030 * it, we account the used space in this range first.
1031 */
1032 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1033 &used_space);
1034 if (ret) {
1035 kfree(devices_info);
1036 return ret;
1037 }
1038
1039 /* calc the free space in [0, skip_space - 1] */
1040 skip_space -= used_space;
1041
1042 /*
1043 * we can use the free space in [0, skip_space - 1], subtract
1044 * it from the total.
1045 */
1046 if (avail_space && avail_space >= skip_space)
1047 avail_space -= skip_space;
1048 else
1049 avail_space = 0;
1050
1051 if (avail_space < min_stripe_size)
1052 continue;
1053
1054 devices_info[i].dev = device;
1055 devices_info[i].max_avail = avail_space;
1056
1057 i++;
1058 }
1059
1060 nr_devices = i;
1061
1062 btrfs_descending_sort_devices(devices_info, nr_devices);
1063
1064 i = nr_devices - 1;
1065 avail_space = 0;
1066 while (nr_devices >= min_stripes) {
1067 if (devices_info[i].max_avail >= min_stripe_size) {
1068 int j;
1069 u64 alloc_size;
1070
1071 avail_space += devices_info[i].max_avail * min_stripes;
1072 alloc_size = devices_info[i].max_avail;
1073 for (j = i + 1 - min_stripes; j <= i; j++)
1074 devices_info[j].max_avail -= alloc_size;
1075 }
1076 i--;
1077 nr_devices--;
1078 }
1079
1080 kfree(devices_info);
1081 *free_bytes = avail_space;
1082 return 0;
1083}
1084
1085static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1086{
1087 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
1088 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1089 struct list_head *head = &root->fs_info->space_info;
1090 struct btrfs_space_info *found;
1091 u64 total_used = 0;
1092 u64 total_free_data = 0;
1093 int bits = dentry->d_sb->s_blocksize_bits;
1094 __be32 *fsid = (__be32 *)root->fs_info->fsid;
1095 int ret;
1096
1097 /* holding chunk_muext to avoid allocating new chunks */
1098 mutex_lock(&root->fs_info->chunk_mutex);
1099 rcu_read_lock();
1100 list_for_each_entry_rcu(found, head, list) {
1101 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1102 total_free_data += found->disk_total - found->disk_used;
1103 total_free_data -=
1104 btrfs_account_ro_block_groups_free_space(found);
1105 }
1106
1107 total_used += found->disk_used;
1108 }
1109 rcu_read_unlock();
1110
1111 buf->f_namelen = BTRFS_NAME_LEN;
1112 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1113 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1114 buf->f_bsize = dentry->d_sb->s_blocksize;
1115 buf->f_type = BTRFS_SUPER_MAGIC;
1116 buf->f_bavail = total_free_data;
1117 ret = btrfs_calc_avail_data_space(root, &total_free_data);
1118 if (ret) {
1119 mutex_unlock(&root->fs_info->chunk_mutex);
1120 return ret;
1121 }
1122 buf->f_bavail += total_free_data;
1123 buf->f_bavail = buf->f_bavail >> bits;
1124 mutex_unlock(&root->fs_info->chunk_mutex);
1125
1126 /* We treat it as constant endianness (it doesn't matter _which_)
1127 because we want the fsid to come out the same whether mounted
1128 on a big-endian or little-endian host */
1129 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1130 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1131 /* Mask in the root object ID too, to disambiguate subvols */
1132 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1133 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1134
1135 return 0;
1136}
1137
1138static struct file_system_type btrfs_fs_type = {
1139 .owner = THIS_MODULE,
1140 .name = "btrfs",
1141 .mount = btrfs_mount,
1142 .kill_sb = kill_anon_super,
1143 .fs_flags = FS_REQUIRES_DEV,
1144};
1145
1146/*
1147 * used by btrfsctl to scan devices when no FS is mounted
1148 */
1149static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1150 unsigned long arg)
1151{
1152 struct btrfs_ioctl_vol_args *vol;
1153 struct btrfs_fs_devices *fs_devices;
1154 int ret = -ENOTTY;
1155
1156 if (!capable(CAP_SYS_ADMIN))
1157 return -EPERM;
1158
1159 vol = memdup_user((void __user *)arg, sizeof(*vol));
1160 if (IS_ERR(vol))
1161 return PTR_ERR(vol);
1162
1163 switch (cmd) {
1164 case BTRFS_IOC_SCAN_DEV:
1165 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1166 &btrfs_fs_type, &fs_devices);
1167 break;
1168 }
1169
1170 kfree(vol);
1171 return ret;
1172}
1173
1174static int btrfs_freeze(struct super_block *sb)
1175{
1176 struct btrfs_root *root = btrfs_sb(sb);
1177 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1178 mutex_lock(&root->fs_info->cleaner_mutex);
1179 return 0;
1180}
1181
1182static int btrfs_unfreeze(struct super_block *sb)
1183{
1184 struct btrfs_root *root = btrfs_sb(sb);
1185 mutex_unlock(&root->fs_info->cleaner_mutex);
1186 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1187 return 0;
1188}
1189
1190static const struct super_operations btrfs_super_ops = {
1191 .drop_inode = btrfs_drop_inode,
1192 .evict_inode = btrfs_evict_inode,
1193 .put_super = btrfs_put_super,
1194 .sync_fs = btrfs_sync_fs,
1195 .show_options = btrfs_show_options,
1196 .write_inode = btrfs_write_inode,
1197 .dirty_inode = btrfs_dirty_inode,
1198 .alloc_inode = btrfs_alloc_inode,
1199 .destroy_inode = btrfs_destroy_inode,
1200 .statfs = btrfs_statfs,
1201 .remount_fs = btrfs_remount,
1202 .freeze_fs = btrfs_freeze,
1203 .unfreeze_fs = btrfs_unfreeze,
1204};
1205
1206static const struct file_operations btrfs_ctl_fops = {
1207 .unlocked_ioctl = btrfs_control_ioctl,
1208 .compat_ioctl = btrfs_control_ioctl,
1209 .owner = THIS_MODULE,
1210 .llseek = noop_llseek,
1211};
1212
1213static struct miscdevice btrfs_misc = {
1214 .minor = BTRFS_MINOR,
1215 .name = "btrfs-control",
1216 .fops = &btrfs_ctl_fops
1217};
1218
1219MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1220MODULE_ALIAS("devname:btrfs-control");
1221
1222static int btrfs_interface_init(void)
1223{
1224 return misc_register(&btrfs_misc);
1225}
1226
1227static void btrfs_interface_exit(void)
1228{
1229 if (misc_deregister(&btrfs_misc) < 0)
1230 printk(KERN_INFO "misc_deregister failed for control device");
1231}
1232
1233static int __init init_btrfs_fs(void)
1234{
1235 int err;
1236
1237 err = btrfs_init_sysfs();
1238 if (err)
1239 return err;
1240
1241 err = btrfs_init_compress();
1242 if (err)
1243 goto free_sysfs;
1244
1245 err = btrfs_init_cachep();
1246 if (err)
1247 goto free_compress;
1248
1249 err = extent_io_init();
1250 if (err)
1251 goto free_cachep;
1252
1253 err = extent_map_init();
1254 if (err)
1255 goto free_extent_io;
1256
1257 err = btrfs_delayed_inode_init();
1258 if (err)
1259 goto free_extent_map;
1260
1261 err = btrfs_interface_init();
1262 if (err)
1263 goto free_delayed_inode;
1264
1265 err = register_filesystem(&btrfs_fs_type);
1266 if (err)
1267 goto unregister_ioctl;
1268
1269 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1270 return 0;
1271
1272unregister_ioctl:
1273 btrfs_interface_exit();
1274free_delayed_inode:
1275 btrfs_delayed_inode_exit();
1276free_extent_map:
1277 extent_map_exit();
1278free_extent_io:
1279 extent_io_exit();
1280free_cachep:
1281 btrfs_destroy_cachep();
1282free_compress:
1283 btrfs_exit_compress();
1284free_sysfs:
1285 btrfs_exit_sysfs();
1286 return err;
1287}
1288
1289static void __exit exit_btrfs_fs(void)
1290{
1291 btrfs_destroy_cachep();
1292 btrfs_delayed_inode_exit();
1293 extent_map_exit();
1294 extent_io_exit();
1295 btrfs_interface_exit();
1296 unregister_filesystem(&btrfs_fs_type);
1297 btrfs_exit_sysfs();
1298 btrfs_cleanup_fs_uuids();
1299 btrfs_exit_compress();
1300}
1301
1302module_init(init_btrfs_fs)
1303module_exit(exit_btrfs_fs)
1304
1305MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/blkdev.h>
7#include <linux/module.h>
8#include <linux/buffer_head.h>
9#include <linux/fs.h>
10#include <linux/pagemap.h>
11#include <linux/highmem.h>
12#include <linux/time.h>
13#include <linux/init.h>
14#include <linux/seq_file.h>
15#include <linux/string.h>
16#include <linux/backing-dev.h>
17#include <linux/mount.h>
18#include <linux/mpage.h>
19#include <linux/swap.h>
20#include <linux/writeback.h>
21#include <linux/statfs.h>
22#include <linux/compat.h>
23#include <linux/parser.h>
24#include <linux/ctype.h>
25#include <linux/namei.h>
26#include <linux/miscdevice.h>
27#include <linux/magic.h>
28#include <linux/slab.h>
29#include <linux/cleancache.h>
30#include <linux/ratelimit.h>
31#include <linux/crc32c.h>
32#include <linux/btrfs.h>
33#include "delayed-inode.h"
34#include "ctree.h"
35#include "disk-io.h"
36#include "transaction.h"
37#include "btrfs_inode.h"
38#include "print-tree.h"
39#include "props.h"
40#include "xattr.h"
41#include "volumes.h"
42#include "export.h"
43#include "compression.h"
44#include "rcu-string.h"
45#include "dev-replace.h"
46#include "free-space-cache.h"
47#include "backref.h"
48#include "tests/btrfs-tests.h"
49
50#include "qgroup.h"
51#define CREATE_TRACE_POINTS
52#include <trace/events/btrfs.h>
53
54static const struct super_operations btrfs_super_ops;
55
56/*
57 * Types for mounting the default subvolume and a subvolume explicitly
58 * requested by subvol=/path. That way the callchain is straightforward and we
59 * don't have to play tricks with the mount options and recursive calls to
60 * btrfs_mount.
61 *
62 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder.
63 */
64static struct file_system_type btrfs_fs_type;
65static struct file_system_type btrfs_root_fs_type;
66
67static int btrfs_remount(struct super_block *sb, int *flags, char *data);
68
69const char *btrfs_decode_error(int errno)
70{
71 char *errstr = "unknown";
72
73 switch (errno) {
74 case -EIO:
75 errstr = "IO failure";
76 break;
77 case -ENOMEM:
78 errstr = "Out of memory";
79 break;
80 case -EROFS:
81 errstr = "Readonly filesystem";
82 break;
83 case -EEXIST:
84 errstr = "Object already exists";
85 break;
86 case -ENOSPC:
87 errstr = "No space left";
88 break;
89 case -ENOENT:
90 errstr = "No such entry";
91 break;
92 }
93
94 return errstr;
95}
96
97/*
98 * __btrfs_handle_fs_error decodes expected errors from the caller and
99 * invokes the approciate error response.
100 */
101__cold
102void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
103 unsigned int line, int errno, const char *fmt, ...)
104{
105 struct super_block *sb = fs_info->sb;
106#ifdef CONFIG_PRINTK
107 const char *errstr;
108#endif
109
110 /*
111 * Special case: if the error is EROFS, and we're already
112 * under SB_RDONLY, then it is safe here.
113 */
114 if (errno == -EROFS && sb_rdonly(sb))
115 return;
116
117#ifdef CONFIG_PRINTK
118 errstr = btrfs_decode_error(errno);
119 if (fmt) {
120 struct va_format vaf;
121 va_list args;
122
123 va_start(args, fmt);
124 vaf.fmt = fmt;
125 vaf.va = &args;
126
127 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
128 sb->s_id, function, line, errno, errstr, &vaf);
129 va_end(args);
130 } else {
131 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
132 sb->s_id, function, line, errno, errstr);
133 }
134#endif
135
136 /*
137 * Today we only save the error info to memory. Long term we'll
138 * also send it down to the disk
139 */
140 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
141
142 /* Don't go through full error handling during mount */
143 if (!(sb->s_flags & SB_BORN))
144 return;
145
146 if (sb_rdonly(sb))
147 return;
148
149 /* btrfs handle error by forcing the filesystem readonly */
150 sb->s_flags |= SB_RDONLY;
151 btrfs_info(fs_info, "forced readonly");
152 /*
153 * Note that a running device replace operation is not canceled here
154 * although there is no way to update the progress. It would add the
155 * risk of a deadlock, therefore the canceling is omitted. The only
156 * penalty is that some I/O remains active until the procedure
157 * completes. The next time when the filesystem is mounted writeable
158 * again, the device replace operation continues.
159 */
160}
161
162#ifdef CONFIG_PRINTK
163static const char * const logtypes[] = {
164 "emergency",
165 "alert",
166 "critical",
167 "error",
168 "warning",
169 "notice",
170 "info",
171 "debug",
172};
173
174
175/*
176 * Use one ratelimit state per log level so that a flood of less important
177 * messages doesn't cause more important ones to be dropped.
178 */
179static struct ratelimit_state printk_limits[] = {
180 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
181 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
182 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
183 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
184 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
185 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
186 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
187 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
188};
189
190void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
191{
192 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
193 struct va_format vaf;
194 va_list args;
195 int kern_level;
196 const char *type = logtypes[4];
197 struct ratelimit_state *ratelimit = &printk_limits[4];
198
199 va_start(args, fmt);
200
201 while ((kern_level = printk_get_level(fmt)) != 0) {
202 size_t size = printk_skip_level(fmt) - fmt;
203
204 if (kern_level >= '0' && kern_level <= '7') {
205 memcpy(lvl, fmt, size);
206 lvl[size] = '\0';
207 type = logtypes[kern_level - '0'];
208 ratelimit = &printk_limits[kern_level - '0'];
209 }
210 fmt += size;
211 }
212
213 vaf.fmt = fmt;
214 vaf.va = &args;
215
216 if (__ratelimit(ratelimit))
217 printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
218 fs_info ? fs_info->sb->s_id : "<unknown>", &vaf);
219
220 va_end(args);
221}
222#endif
223
224/*
225 * We only mark the transaction aborted and then set the file system read-only.
226 * This will prevent new transactions from starting or trying to join this
227 * one.
228 *
229 * This means that error recovery at the call site is limited to freeing
230 * any local memory allocations and passing the error code up without
231 * further cleanup. The transaction should complete as it normally would
232 * in the call path but will return -EIO.
233 *
234 * We'll complete the cleanup in btrfs_end_transaction and
235 * btrfs_commit_transaction.
236 */
237__cold
238void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
239 const char *function,
240 unsigned int line, int errno)
241{
242 struct btrfs_fs_info *fs_info = trans->fs_info;
243
244 trans->aborted = errno;
245 /* Nothing used. The other threads that have joined this
246 * transaction may be able to continue. */
247 if (!trans->dirty && list_empty(&trans->new_bgs)) {
248 const char *errstr;
249
250 errstr = btrfs_decode_error(errno);
251 btrfs_warn(fs_info,
252 "%s:%d: Aborting unused transaction(%s).",
253 function, line, errstr);
254 return;
255 }
256 WRITE_ONCE(trans->transaction->aborted, errno);
257 /* Wake up anybody who may be waiting on this transaction */
258 wake_up(&fs_info->transaction_wait);
259 wake_up(&fs_info->transaction_blocked_wait);
260 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL);
261}
262/*
263 * __btrfs_panic decodes unexpected, fatal errors from the caller,
264 * issues an alert, and either panics or BUGs, depending on mount options.
265 */
266__cold
267void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
268 unsigned int line, int errno, const char *fmt, ...)
269{
270 char *s_id = "<unknown>";
271 const char *errstr;
272 struct va_format vaf = { .fmt = fmt };
273 va_list args;
274
275 if (fs_info)
276 s_id = fs_info->sb->s_id;
277
278 va_start(args, fmt);
279 vaf.va = &args;
280
281 errstr = btrfs_decode_error(errno);
282 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
283 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
284 s_id, function, line, &vaf, errno, errstr);
285
286 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
287 function, line, &vaf, errno, errstr);
288 va_end(args);
289 /* Caller calls BUG() */
290}
291
292static void btrfs_put_super(struct super_block *sb)
293{
294 close_ctree(btrfs_sb(sb));
295}
296
297enum {
298 Opt_acl, Opt_noacl,
299 Opt_clear_cache,
300 Opt_commit_interval,
301 Opt_compress,
302 Opt_compress_force,
303 Opt_compress_force_type,
304 Opt_compress_type,
305 Opt_degraded,
306 Opt_device,
307 Opt_fatal_errors,
308 Opt_flushoncommit, Opt_noflushoncommit,
309 Opt_inode_cache, Opt_noinode_cache,
310 Opt_max_inline,
311 Opt_barrier, Opt_nobarrier,
312 Opt_datacow, Opt_nodatacow,
313 Opt_datasum, Opt_nodatasum,
314 Opt_defrag, Opt_nodefrag,
315 Opt_discard, Opt_nodiscard,
316 Opt_nologreplay,
317 Opt_norecovery,
318 Opt_ratio,
319 Opt_rescan_uuid_tree,
320 Opt_skip_balance,
321 Opt_space_cache, Opt_no_space_cache,
322 Opt_space_cache_version,
323 Opt_ssd, Opt_nossd,
324 Opt_ssd_spread, Opt_nossd_spread,
325 Opt_subvol,
326 Opt_subvolid,
327 Opt_thread_pool,
328 Opt_treelog, Opt_notreelog,
329 Opt_usebackuproot,
330 Opt_user_subvol_rm_allowed,
331
332 /* Deprecated options */
333 Opt_alloc_start,
334 Opt_recovery,
335 Opt_subvolrootid,
336
337 /* Debugging options */
338 Opt_check_integrity,
339 Opt_check_integrity_including_extent_data,
340 Opt_check_integrity_print_mask,
341 Opt_enospc_debug, Opt_noenospc_debug,
342#ifdef CONFIG_BTRFS_DEBUG
343 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
344#endif
345#ifdef CONFIG_BTRFS_FS_REF_VERIFY
346 Opt_ref_verify,
347#endif
348 Opt_err,
349};
350
351static const match_table_t tokens = {
352 {Opt_acl, "acl"},
353 {Opt_noacl, "noacl"},
354 {Opt_clear_cache, "clear_cache"},
355 {Opt_commit_interval, "commit=%u"},
356 {Opt_compress, "compress"},
357 {Opt_compress_type, "compress=%s"},
358 {Opt_compress_force, "compress-force"},
359 {Opt_compress_force_type, "compress-force=%s"},
360 {Opt_degraded, "degraded"},
361 {Opt_device, "device=%s"},
362 {Opt_fatal_errors, "fatal_errors=%s"},
363 {Opt_flushoncommit, "flushoncommit"},
364 {Opt_noflushoncommit, "noflushoncommit"},
365 {Opt_inode_cache, "inode_cache"},
366 {Opt_noinode_cache, "noinode_cache"},
367 {Opt_max_inline, "max_inline=%s"},
368 {Opt_barrier, "barrier"},
369 {Opt_nobarrier, "nobarrier"},
370 {Opt_datacow, "datacow"},
371 {Opt_nodatacow, "nodatacow"},
372 {Opt_datasum, "datasum"},
373 {Opt_nodatasum, "nodatasum"},
374 {Opt_defrag, "autodefrag"},
375 {Opt_nodefrag, "noautodefrag"},
376 {Opt_discard, "discard"},
377 {Opt_nodiscard, "nodiscard"},
378 {Opt_nologreplay, "nologreplay"},
379 {Opt_norecovery, "norecovery"},
380 {Opt_ratio, "metadata_ratio=%u"},
381 {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
382 {Opt_skip_balance, "skip_balance"},
383 {Opt_space_cache, "space_cache"},
384 {Opt_no_space_cache, "nospace_cache"},
385 {Opt_space_cache_version, "space_cache=%s"},
386 {Opt_ssd, "ssd"},
387 {Opt_nossd, "nossd"},
388 {Opt_ssd_spread, "ssd_spread"},
389 {Opt_nossd_spread, "nossd_spread"},
390 {Opt_subvol, "subvol=%s"},
391 {Opt_subvolid, "subvolid=%s"},
392 {Opt_thread_pool, "thread_pool=%u"},
393 {Opt_treelog, "treelog"},
394 {Opt_notreelog, "notreelog"},
395 {Opt_usebackuproot, "usebackuproot"},
396 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
397
398 /* Deprecated options */
399 {Opt_alloc_start, "alloc_start=%s"},
400 {Opt_recovery, "recovery"},
401 {Opt_subvolrootid, "subvolrootid=%d"},
402
403 /* Debugging options */
404 {Opt_check_integrity, "check_int"},
405 {Opt_check_integrity_including_extent_data, "check_int_data"},
406 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"},
407 {Opt_enospc_debug, "enospc_debug"},
408 {Opt_noenospc_debug, "noenospc_debug"},
409#ifdef CONFIG_BTRFS_DEBUG
410 {Opt_fragment_data, "fragment=data"},
411 {Opt_fragment_metadata, "fragment=metadata"},
412 {Opt_fragment_all, "fragment=all"},
413#endif
414#ifdef CONFIG_BTRFS_FS_REF_VERIFY
415 {Opt_ref_verify, "ref_verify"},
416#endif
417 {Opt_err, NULL},
418};
419
420/*
421 * Regular mount options parser. Everything that is needed only when
422 * reading in a new superblock is parsed here.
423 * XXX JDM: This needs to be cleaned up for remount.
424 */
425int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
426 unsigned long new_flags)
427{
428 substring_t args[MAX_OPT_ARGS];
429 char *p, *num;
430 u64 cache_gen;
431 int intarg;
432 int ret = 0;
433 char *compress_type;
434 bool compress_force = false;
435 enum btrfs_compression_type saved_compress_type;
436 bool saved_compress_force;
437 int no_compress = 0;
438
439 cache_gen = btrfs_super_cache_generation(info->super_copy);
440 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
441 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
442 else if (cache_gen)
443 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
444
445 /*
446 * Even the options are empty, we still need to do extra check
447 * against new flags
448 */
449 if (!options)
450 goto check;
451
452 while ((p = strsep(&options, ",")) != NULL) {
453 int token;
454 if (!*p)
455 continue;
456
457 token = match_token(p, tokens, args);
458 switch (token) {
459 case Opt_degraded:
460 btrfs_info(info, "allowing degraded mounts");
461 btrfs_set_opt(info->mount_opt, DEGRADED);
462 break;
463 case Opt_subvol:
464 case Opt_subvolid:
465 case Opt_subvolrootid:
466 case Opt_device:
467 /*
468 * These are parsed by btrfs_parse_subvol_options
469 * and btrfs_parse_early_options
470 * and can be happily ignored here.
471 */
472 break;
473 case Opt_nodatasum:
474 btrfs_set_and_info(info, NODATASUM,
475 "setting nodatasum");
476 break;
477 case Opt_datasum:
478 if (btrfs_test_opt(info, NODATASUM)) {
479 if (btrfs_test_opt(info, NODATACOW))
480 btrfs_info(info,
481 "setting datasum, datacow enabled");
482 else
483 btrfs_info(info, "setting datasum");
484 }
485 btrfs_clear_opt(info->mount_opt, NODATACOW);
486 btrfs_clear_opt(info->mount_opt, NODATASUM);
487 break;
488 case Opt_nodatacow:
489 if (!btrfs_test_opt(info, NODATACOW)) {
490 if (!btrfs_test_opt(info, COMPRESS) ||
491 !btrfs_test_opt(info, FORCE_COMPRESS)) {
492 btrfs_info(info,
493 "setting nodatacow, compression disabled");
494 } else {
495 btrfs_info(info, "setting nodatacow");
496 }
497 }
498 btrfs_clear_opt(info->mount_opt, COMPRESS);
499 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
500 btrfs_set_opt(info->mount_opt, NODATACOW);
501 btrfs_set_opt(info->mount_opt, NODATASUM);
502 break;
503 case Opt_datacow:
504 btrfs_clear_and_info(info, NODATACOW,
505 "setting datacow");
506 break;
507 case Opt_compress_force:
508 case Opt_compress_force_type:
509 compress_force = true;
510 /* Fallthrough */
511 case Opt_compress:
512 case Opt_compress_type:
513 saved_compress_type = btrfs_test_opt(info,
514 COMPRESS) ?
515 info->compress_type : BTRFS_COMPRESS_NONE;
516 saved_compress_force =
517 btrfs_test_opt(info, FORCE_COMPRESS);
518 if (token == Opt_compress ||
519 token == Opt_compress_force ||
520 strncmp(args[0].from, "zlib", 4) == 0) {
521 compress_type = "zlib";
522
523 info->compress_type = BTRFS_COMPRESS_ZLIB;
524 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
525 /*
526 * args[0] contains uninitialized data since
527 * for these tokens we don't expect any
528 * parameter.
529 */
530 if (token != Opt_compress &&
531 token != Opt_compress_force)
532 info->compress_level =
533 btrfs_compress_str2level(args[0].from);
534 btrfs_set_opt(info->mount_opt, COMPRESS);
535 btrfs_clear_opt(info->mount_opt, NODATACOW);
536 btrfs_clear_opt(info->mount_opt, NODATASUM);
537 no_compress = 0;
538 } else if (strncmp(args[0].from, "lzo", 3) == 0) {
539 compress_type = "lzo";
540 info->compress_type = BTRFS_COMPRESS_LZO;
541 btrfs_set_opt(info->mount_opt, COMPRESS);
542 btrfs_clear_opt(info->mount_opt, NODATACOW);
543 btrfs_clear_opt(info->mount_opt, NODATASUM);
544 btrfs_set_fs_incompat(info, COMPRESS_LZO);
545 no_compress = 0;
546 } else if (strcmp(args[0].from, "zstd") == 0) {
547 compress_type = "zstd";
548 info->compress_type = BTRFS_COMPRESS_ZSTD;
549 btrfs_set_opt(info->mount_opt, COMPRESS);
550 btrfs_clear_opt(info->mount_opt, NODATACOW);
551 btrfs_clear_opt(info->mount_opt, NODATASUM);
552 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
553 no_compress = 0;
554 } else if (strncmp(args[0].from, "no", 2) == 0) {
555 compress_type = "no";
556 btrfs_clear_opt(info->mount_opt, COMPRESS);
557 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
558 compress_force = false;
559 no_compress++;
560 } else {
561 ret = -EINVAL;
562 goto out;
563 }
564
565 if (compress_force) {
566 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
567 } else {
568 /*
569 * If we remount from compress-force=xxx to
570 * compress=xxx, we need clear FORCE_COMPRESS
571 * flag, otherwise, there is no way for users
572 * to disable forcible compression separately.
573 */
574 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
575 }
576 if ((btrfs_test_opt(info, COMPRESS) &&
577 (info->compress_type != saved_compress_type ||
578 compress_force != saved_compress_force)) ||
579 (!btrfs_test_opt(info, COMPRESS) &&
580 no_compress == 1)) {
581 btrfs_info(info, "%s %s compression, level %d",
582 (compress_force) ? "force" : "use",
583 compress_type, info->compress_level);
584 }
585 compress_force = false;
586 break;
587 case Opt_ssd:
588 btrfs_set_and_info(info, SSD,
589 "enabling ssd optimizations");
590 btrfs_clear_opt(info->mount_opt, NOSSD);
591 break;
592 case Opt_ssd_spread:
593 btrfs_set_and_info(info, SSD,
594 "enabling ssd optimizations");
595 btrfs_set_and_info(info, SSD_SPREAD,
596 "using spread ssd allocation scheme");
597 btrfs_clear_opt(info->mount_opt, NOSSD);
598 break;
599 case Opt_nossd:
600 btrfs_set_opt(info->mount_opt, NOSSD);
601 btrfs_clear_and_info(info, SSD,
602 "not using ssd optimizations");
603 /* Fallthrough */
604 case Opt_nossd_spread:
605 btrfs_clear_and_info(info, SSD_SPREAD,
606 "not using spread ssd allocation scheme");
607 break;
608 case Opt_barrier:
609 btrfs_clear_and_info(info, NOBARRIER,
610 "turning on barriers");
611 break;
612 case Opt_nobarrier:
613 btrfs_set_and_info(info, NOBARRIER,
614 "turning off barriers");
615 break;
616 case Opt_thread_pool:
617 ret = match_int(&args[0], &intarg);
618 if (ret) {
619 goto out;
620 } else if (intarg == 0) {
621 ret = -EINVAL;
622 goto out;
623 }
624 info->thread_pool_size = intarg;
625 break;
626 case Opt_max_inline:
627 num = match_strdup(&args[0]);
628 if (num) {
629 info->max_inline = memparse(num, NULL);
630 kfree(num);
631
632 if (info->max_inline) {
633 info->max_inline = min_t(u64,
634 info->max_inline,
635 info->sectorsize);
636 }
637 btrfs_info(info, "max_inline at %llu",
638 info->max_inline);
639 } else {
640 ret = -ENOMEM;
641 goto out;
642 }
643 break;
644 case Opt_alloc_start:
645 btrfs_info(info,
646 "option alloc_start is obsolete, ignored");
647 break;
648 case Opt_acl:
649#ifdef CONFIG_BTRFS_FS_POSIX_ACL
650 info->sb->s_flags |= SB_POSIXACL;
651 break;
652#else
653 btrfs_err(info, "support for ACL not compiled in!");
654 ret = -EINVAL;
655 goto out;
656#endif
657 case Opt_noacl:
658 info->sb->s_flags &= ~SB_POSIXACL;
659 break;
660 case Opt_notreelog:
661 btrfs_set_and_info(info, NOTREELOG,
662 "disabling tree log");
663 break;
664 case Opt_treelog:
665 btrfs_clear_and_info(info, NOTREELOG,
666 "enabling tree log");
667 break;
668 case Opt_norecovery:
669 case Opt_nologreplay:
670 btrfs_set_and_info(info, NOLOGREPLAY,
671 "disabling log replay at mount time");
672 break;
673 case Opt_flushoncommit:
674 btrfs_set_and_info(info, FLUSHONCOMMIT,
675 "turning on flush-on-commit");
676 break;
677 case Opt_noflushoncommit:
678 btrfs_clear_and_info(info, FLUSHONCOMMIT,
679 "turning off flush-on-commit");
680 break;
681 case Opt_ratio:
682 ret = match_int(&args[0], &intarg);
683 if (ret)
684 goto out;
685 info->metadata_ratio = intarg;
686 btrfs_info(info, "metadata ratio %u",
687 info->metadata_ratio);
688 break;
689 case Opt_discard:
690 btrfs_set_and_info(info, DISCARD,
691 "turning on discard");
692 break;
693 case Opt_nodiscard:
694 btrfs_clear_and_info(info, DISCARD,
695 "turning off discard");
696 break;
697 case Opt_space_cache:
698 case Opt_space_cache_version:
699 if (token == Opt_space_cache ||
700 strcmp(args[0].from, "v1") == 0) {
701 btrfs_clear_opt(info->mount_opt,
702 FREE_SPACE_TREE);
703 btrfs_set_and_info(info, SPACE_CACHE,
704 "enabling disk space caching");
705 } else if (strcmp(args[0].from, "v2") == 0) {
706 btrfs_clear_opt(info->mount_opt,
707 SPACE_CACHE);
708 btrfs_set_and_info(info, FREE_SPACE_TREE,
709 "enabling free space tree");
710 } else {
711 ret = -EINVAL;
712 goto out;
713 }
714 break;
715 case Opt_rescan_uuid_tree:
716 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
717 break;
718 case Opt_no_space_cache:
719 if (btrfs_test_opt(info, SPACE_CACHE)) {
720 btrfs_clear_and_info(info, SPACE_CACHE,
721 "disabling disk space caching");
722 }
723 if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
724 btrfs_clear_and_info(info, FREE_SPACE_TREE,
725 "disabling free space tree");
726 }
727 break;
728 case Opt_inode_cache:
729 btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
730 "enabling inode map caching");
731 break;
732 case Opt_noinode_cache:
733 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE,
734 "disabling inode map caching");
735 break;
736 case Opt_clear_cache:
737 btrfs_set_and_info(info, CLEAR_CACHE,
738 "force clearing of disk cache");
739 break;
740 case Opt_user_subvol_rm_allowed:
741 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
742 break;
743 case Opt_enospc_debug:
744 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
745 break;
746 case Opt_noenospc_debug:
747 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
748 break;
749 case Opt_defrag:
750 btrfs_set_and_info(info, AUTO_DEFRAG,
751 "enabling auto defrag");
752 break;
753 case Opt_nodefrag:
754 btrfs_clear_and_info(info, AUTO_DEFRAG,
755 "disabling auto defrag");
756 break;
757 case Opt_recovery:
758 btrfs_warn(info,
759 "'recovery' is deprecated, use 'usebackuproot' instead");
760 case Opt_usebackuproot:
761 btrfs_info(info,
762 "trying to use backup root at mount time");
763 btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
764 break;
765 case Opt_skip_balance:
766 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
767 break;
768#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
769 case Opt_check_integrity_including_extent_data:
770 btrfs_info(info,
771 "enabling check integrity including extent data");
772 btrfs_set_opt(info->mount_opt,
773 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
774 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
775 break;
776 case Opt_check_integrity:
777 btrfs_info(info, "enabling check integrity");
778 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
779 break;
780 case Opt_check_integrity_print_mask:
781 ret = match_int(&args[0], &intarg);
782 if (ret)
783 goto out;
784 info->check_integrity_print_mask = intarg;
785 btrfs_info(info, "check_integrity_print_mask 0x%x",
786 info->check_integrity_print_mask);
787 break;
788#else
789 case Opt_check_integrity_including_extent_data:
790 case Opt_check_integrity:
791 case Opt_check_integrity_print_mask:
792 btrfs_err(info,
793 "support for check_integrity* not compiled in!");
794 ret = -EINVAL;
795 goto out;
796#endif
797 case Opt_fatal_errors:
798 if (strcmp(args[0].from, "panic") == 0)
799 btrfs_set_opt(info->mount_opt,
800 PANIC_ON_FATAL_ERROR);
801 else if (strcmp(args[0].from, "bug") == 0)
802 btrfs_clear_opt(info->mount_opt,
803 PANIC_ON_FATAL_ERROR);
804 else {
805 ret = -EINVAL;
806 goto out;
807 }
808 break;
809 case Opt_commit_interval:
810 intarg = 0;
811 ret = match_int(&args[0], &intarg);
812 if (ret)
813 goto out;
814 if (intarg == 0) {
815 btrfs_info(info,
816 "using default commit interval %us",
817 BTRFS_DEFAULT_COMMIT_INTERVAL);
818 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
819 } else if (intarg > 300) {
820 btrfs_warn(info, "excessive commit interval %d",
821 intarg);
822 }
823 info->commit_interval = intarg;
824 break;
825#ifdef CONFIG_BTRFS_DEBUG
826 case Opt_fragment_all:
827 btrfs_info(info, "fragmenting all space");
828 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
829 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
830 break;
831 case Opt_fragment_metadata:
832 btrfs_info(info, "fragmenting metadata");
833 btrfs_set_opt(info->mount_opt,
834 FRAGMENT_METADATA);
835 break;
836 case Opt_fragment_data:
837 btrfs_info(info, "fragmenting data");
838 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
839 break;
840#endif
841#ifdef CONFIG_BTRFS_FS_REF_VERIFY
842 case Opt_ref_verify:
843 btrfs_info(info, "doing ref verification");
844 btrfs_set_opt(info->mount_opt, REF_VERIFY);
845 break;
846#endif
847 case Opt_err:
848 btrfs_info(info, "unrecognized mount option '%s'", p);
849 ret = -EINVAL;
850 goto out;
851 default:
852 break;
853 }
854 }
855check:
856 /*
857 * Extra check for current option against current flag
858 */
859 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & SB_RDONLY)) {
860 btrfs_err(info,
861 "nologreplay must be used with ro mount option");
862 ret = -EINVAL;
863 }
864out:
865 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
866 !btrfs_test_opt(info, FREE_SPACE_TREE) &&
867 !btrfs_test_opt(info, CLEAR_CACHE)) {
868 btrfs_err(info, "cannot disable free space tree");
869 ret = -EINVAL;
870
871 }
872 if (!ret && btrfs_test_opt(info, SPACE_CACHE))
873 btrfs_info(info, "disk space caching is enabled");
874 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
875 btrfs_info(info, "using free space tree");
876 return ret;
877}
878
879/*
880 * Parse mount options that are required early in the mount process.
881 *
882 * All other options will be parsed on much later in the mount process and
883 * only when we need to allocate a new super block.
884 */
885static int btrfs_parse_early_options(const char *options, fmode_t flags,
886 void *holder, struct btrfs_fs_devices **fs_devices)
887{
888 substring_t args[MAX_OPT_ARGS];
889 char *device_name, *opts, *orig, *p;
890 int error = 0;
891
892 if (!options)
893 return 0;
894
895 /*
896 * strsep changes the string, duplicate it because btrfs_parse_options
897 * gets called later
898 */
899 opts = kstrdup(options, GFP_KERNEL);
900 if (!opts)
901 return -ENOMEM;
902 orig = opts;
903
904 while ((p = strsep(&opts, ",")) != NULL) {
905 int token;
906
907 if (!*p)
908 continue;
909
910 token = match_token(p, tokens, args);
911 if (token == Opt_device) {
912 device_name = match_strdup(&args[0]);
913 if (!device_name) {
914 error = -ENOMEM;
915 goto out;
916 }
917 error = btrfs_scan_one_device(device_name,
918 flags, holder, fs_devices);
919 kfree(device_name);
920 if (error)
921 goto out;
922 }
923 }
924
925out:
926 kfree(orig);
927 return error;
928}
929
930/*
931 * Parse mount options that are related to subvolume id
932 *
933 * The value is later passed to mount_subvol()
934 */
935static int btrfs_parse_subvol_options(const char *options, fmode_t flags,
936 char **subvol_name, u64 *subvol_objectid)
937{
938 substring_t args[MAX_OPT_ARGS];
939 char *opts, *orig, *p;
940 int error = 0;
941 u64 subvolid;
942
943 if (!options)
944 return 0;
945
946 /*
947 * strsep changes the string, duplicate it because
948 * btrfs_parse_early_options gets called later
949 */
950 opts = kstrdup(options, GFP_KERNEL);
951 if (!opts)
952 return -ENOMEM;
953 orig = opts;
954
955 while ((p = strsep(&opts, ",")) != NULL) {
956 int token;
957 if (!*p)
958 continue;
959
960 token = match_token(p, tokens, args);
961 switch (token) {
962 case Opt_subvol:
963 kfree(*subvol_name);
964 *subvol_name = match_strdup(&args[0]);
965 if (!*subvol_name) {
966 error = -ENOMEM;
967 goto out;
968 }
969 break;
970 case Opt_subvolid:
971 error = match_u64(&args[0], &subvolid);
972 if (error)
973 goto out;
974
975 /* we want the original fs_tree */
976 if (subvolid == 0)
977 subvolid = BTRFS_FS_TREE_OBJECTID;
978
979 *subvol_objectid = subvolid;
980 break;
981 case Opt_subvolrootid:
982 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n");
983 break;
984 default:
985 break;
986 }
987 }
988
989out:
990 kfree(orig);
991 return error;
992}
993
994static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
995 u64 subvol_objectid)
996{
997 struct btrfs_root *root = fs_info->tree_root;
998 struct btrfs_root *fs_root;
999 struct btrfs_root_ref *root_ref;
1000 struct btrfs_inode_ref *inode_ref;
1001 struct btrfs_key key;
1002 struct btrfs_path *path = NULL;
1003 char *name = NULL, *ptr;
1004 u64 dirid;
1005 int len;
1006 int ret;
1007
1008 path = btrfs_alloc_path();
1009 if (!path) {
1010 ret = -ENOMEM;
1011 goto err;
1012 }
1013 path->leave_spinning = 1;
1014
1015 name = kmalloc(PATH_MAX, GFP_KERNEL);
1016 if (!name) {
1017 ret = -ENOMEM;
1018 goto err;
1019 }
1020 ptr = name + PATH_MAX - 1;
1021 ptr[0] = '\0';
1022
1023 /*
1024 * Walk up the subvolume trees in the tree of tree roots by root
1025 * backrefs until we hit the top-level subvolume.
1026 */
1027 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
1028 key.objectid = subvol_objectid;
1029 key.type = BTRFS_ROOT_BACKREF_KEY;
1030 key.offset = (u64)-1;
1031
1032 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1033 if (ret < 0) {
1034 goto err;
1035 } else if (ret > 0) {
1036 ret = btrfs_previous_item(root, path, subvol_objectid,
1037 BTRFS_ROOT_BACKREF_KEY);
1038 if (ret < 0) {
1039 goto err;
1040 } else if (ret > 0) {
1041 ret = -ENOENT;
1042 goto err;
1043 }
1044 }
1045
1046 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1047 subvol_objectid = key.offset;
1048
1049 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1050 struct btrfs_root_ref);
1051 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
1052 ptr -= len + 1;
1053 if (ptr < name) {
1054 ret = -ENAMETOOLONG;
1055 goto err;
1056 }
1057 read_extent_buffer(path->nodes[0], ptr + 1,
1058 (unsigned long)(root_ref + 1), len);
1059 ptr[0] = '/';
1060 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
1061 btrfs_release_path(path);
1062
1063 key.objectid = subvol_objectid;
1064 key.type = BTRFS_ROOT_ITEM_KEY;
1065 key.offset = (u64)-1;
1066 fs_root = btrfs_read_fs_root_no_name(fs_info, &key);
1067 if (IS_ERR(fs_root)) {
1068 ret = PTR_ERR(fs_root);
1069 goto err;
1070 }
1071
1072 /*
1073 * Walk up the filesystem tree by inode refs until we hit the
1074 * root directory.
1075 */
1076 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
1077 key.objectid = dirid;
1078 key.type = BTRFS_INODE_REF_KEY;
1079 key.offset = (u64)-1;
1080
1081 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
1082 if (ret < 0) {
1083 goto err;
1084 } else if (ret > 0) {
1085 ret = btrfs_previous_item(fs_root, path, dirid,
1086 BTRFS_INODE_REF_KEY);
1087 if (ret < 0) {
1088 goto err;
1089 } else if (ret > 0) {
1090 ret = -ENOENT;
1091 goto err;
1092 }
1093 }
1094
1095 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1096 dirid = key.offset;
1097
1098 inode_ref = btrfs_item_ptr(path->nodes[0],
1099 path->slots[0],
1100 struct btrfs_inode_ref);
1101 len = btrfs_inode_ref_name_len(path->nodes[0],
1102 inode_ref);
1103 ptr -= len + 1;
1104 if (ptr < name) {
1105 ret = -ENAMETOOLONG;
1106 goto err;
1107 }
1108 read_extent_buffer(path->nodes[0], ptr + 1,
1109 (unsigned long)(inode_ref + 1), len);
1110 ptr[0] = '/';
1111 btrfs_release_path(path);
1112 }
1113 }
1114
1115 btrfs_free_path(path);
1116 if (ptr == name + PATH_MAX - 1) {
1117 name[0] = '/';
1118 name[1] = '\0';
1119 } else {
1120 memmove(name, ptr, name + PATH_MAX - ptr);
1121 }
1122 return name;
1123
1124err:
1125 btrfs_free_path(path);
1126 kfree(name);
1127 return ERR_PTR(ret);
1128}
1129
1130static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1131{
1132 struct btrfs_root *root = fs_info->tree_root;
1133 struct btrfs_dir_item *di;
1134 struct btrfs_path *path;
1135 struct btrfs_key location;
1136 u64 dir_id;
1137
1138 path = btrfs_alloc_path();
1139 if (!path)
1140 return -ENOMEM;
1141 path->leave_spinning = 1;
1142
1143 /*
1144 * Find the "default" dir item which points to the root item that we
1145 * will mount by default if we haven't been given a specific subvolume
1146 * to mount.
1147 */
1148 dir_id = btrfs_super_root_dir(fs_info->super_copy);
1149 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
1150 if (IS_ERR(di)) {
1151 btrfs_free_path(path);
1152 return PTR_ERR(di);
1153 }
1154 if (!di) {
1155 /*
1156 * Ok the default dir item isn't there. This is weird since
1157 * it's always been there, but don't freak out, just try and
1158 * mount the top-level subvolume.
1159 */
1160 btrfs_free_path(path);
1161 *objectid = BTRFS_FS_TREE_OBJECTID;
1162 return 0;
1163 }
1164
1165 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1166 btrfs_free_path(path);
1167 *objectid = location.objectid;
1168 return 0;
1169}
1170
1171static int btrfs_fill_super(struct super_block *sb,
1172 struct btrfs_fs_devices *fs_devices,
1173 void *data)
1174{
1175 struct inode *inode;
1176 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1177 struct btrfs_key key;
1178 int err;
1179
1180 sb->s_maxbytes = MAX_LFS_FILESIZE;
1181 sb->s_magic = BTRFS_SUPER_MAGIC;
1182 sb->s_op = &btrfs_super_ops;
1183 sb->s_d_op = &btrfs_dentry_operations;
1184 sb->s_export_op = &btrfs_export_ops;
1185 sb->s_xattr = btrfs_xattr_handlers;
1186 sb->s_time_gran = 1;
1187#ifdef CONFIG_BTRFS_FS_POSIX_ACL
1188 sb->s_flags |= SB_POSIXACL;
1189#endif
1190 sb->s_flags |= SB_I_VERSION;
1191 sb->s_iflags |= SB_I_CGROUPWB;
1192
1193 err = super_setup_bdi(sb);
1194 if (err) {
1195 btrfs_err(fs_info, "super_setup_bdi failed");
1196 return err;
1197 }
1198
1199 err = open_ctree(sb, fs_devices, (char *)data);
1200 if (err) {
1201 btrfs_err(fs_info, "open_ctree failed");
1202 return err;
1203 }
1204
1205 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1206 key.type = BTRFS_INODE_ITEM_KEY;
1207 key.offset = 0;
1208 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
1209 if (IS_ERR(inode)) {
1210 err = PTR_ERR(inode);
1211 goto fail_close;
1212 }
1213
1214 sb->s_root = d_make_root(inode);
1215 if (!sb->s_root) {
1216 err = -ENOMEM;
1217 goto fail_close;
1218 }
1219
1220 cleancache_init_fs(sb);
1221 sb->s_flags |= SB_ACTIVE;
1222 return 0;
1223
1224fail_close:
1225 close_ctree(fs_info);
1226 return err;
1227}
1228
1229int btrfs_sync_fs(struct super_block *sb, int wait)
1230{
1231 struct btrfs_trans_handle *trans;
1232 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1233 struct btrfs_root *root = fs_info->tree_root;
1234
1235 trace_btrfs_sync_fs(fs_info, wait);
1236
1237 if (!wait) {
1238 filemap_flush(fs_info->btree_inode->i_mapping);
1239 return 0;
1240 }
1241
1242 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1243
1244 trans = btrfs_attach_transaction_barrier(root);
1245 if (IS_ERR(trans)) {
1246 /* no transaction, don't bother */
1247 if (PTR_ERR(trans) == -ENOENT) {
1248 /*
1249 * Exit unless we have some pending changes
1250 * that need to go through commit
1251 */
1252 if (fs_info->pending_changes == 0)
1253 return 0;
1254 /*
1255 * A non-blocking test if the fs is frozen. We must not
1256 * start a new transaction here otherwise a deadlock
1257 * happens. The pending operations are delayed to the
1258 * next commit after thawing.
1259 */
1260 if (sb_start_write_trylock(sb))
1261 sb_end_write(sb);
1262 else
1263 return 0;
1264 trans = btrfs_start_transaction(root, 0);
1265 }
1266 if (IS_ERR(trans))
1267 return PTR_ERR(trans);
1268 }
1269 return btrfs_commit_transaction(trans);
1270}
1271
1272static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1273{
1274 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1275 const char *compress_type;
1276
1277 if (btrfs_test_opt(info, DEGRADED))
1278 seq_puts(seq, ",degraded");
1279 if (btrfs_test_opt(info, NODATASUM))
1280 seq_puts(seq, ",nodatasum");
1281 if (btrfs_test_opt(info, NODATACOW))
1282 seq_puts(seq, ",nodatacow");
1283 if (btrfs_test_opt(info, NOBARRIER))
1284 seq_puts(seq, ",nobarrier");
1285 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1286 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1287 if (info->thread_pool_size != min_t(unsigned long,
1288 num_online_cpus() + 2, 8))
1289 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1290 if (btrfs_test_opt(info, COMPRESS)) {
1291 compress_type = btrfs_compress_type2str(info->compress_type);
1292 if (btrfs_test_opt(info, FORCE_COMPRESS))
1293 seq_printf(seq, ",compress-force=%s", compress_type);
1294 else
1295 seq_printf(seq, ",compress=%s", compress_type);
1296 if (info->compress_level)
1297 seq_printf(seq, ":%d", info->compress_level);
1298 }
1299 if (btrfs_test_opt(info, NOSSD))
1300 seq_puts(seq, ",nossd");
1301 if (btrfs_test_opt(info, SSD_SPREAD))
1302 seq_puts(seq, ",ssd_spread");
1303 else if (btrfs_test_opt(info, SSD))
1304 seq_puts(seq, ",ssd");
1305 if (btrfs_test_opt(info, NOTREELOG))
1306 seq_puts(seq, ",notreelog");
1307 if (btrfs_test_opt(info, NOLOGREPLAY))
1308 seq_puts(seq, ",nologreplay");
1309 if (btrfs_test_opt(info, FLUSHONCOMMIT))
1310 seq_puts(seq, ",flushoncommit");
1311 if (btrfs_test_opt(info, DISCARD))
1312 seq_puts(seq, ",discard");
1313 if (!(info->sb->s_flags & SB_POSIXACL))
1314 seq_puts(seq, ",noacl");
1315 if (btrfs_test_opt(info, SPACE_CACHE))
1316 seq_puts(seq, ",space_cache");
1317 else if (btrfs_test_opt(info, FREE_SPACE_TREE))
1318 seq_puts(seq, ",space_cache=v2");
1319 else
1320 seq_puts(seq, ",nospace_cache");
1321 if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1322 seq_puts(seq, ",rescan_uuid_tree");
1323 if (btrfs_test_opt(info, CLEAR_CACHE))
1324 seq_puts(seq, ",clear_cache");
1325 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1326 seq_puts(seq, ",user_subvol_rm_allowed");
1327 if (btrfs_test_opt(info, ENOSPC_DEBUG))
1328 seq_puts(seq, ",enospc_debug");
1329 if (btrfs_test_opt(info, AUTO_DEFRAG))
1330 seq_puts(seq, ",autodefrag");
1331 if (btrfs_test_opt(info, INODE_MAP_CACHE))
1332 seq_puts(seq, ",inode_cache");
1333 if (btrfs_test_opt(info, SKIP_BALANCE))
1334 seq_puts(seq, ",skip_balance");
1335#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1336 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1337 seq_puts(seq, ",check_int_data");
1338 else if (btrfs_test_opt(info, CHECK_INTEGRITY))
1339 seq_puts(seq, ",check_int");
1340 if (info->check_integrity_print_mask)
1341 seq_printf(seq, ",check_int_print_mask=%d",
1342 info->check_integrity_print_mask);
1343#endif
1344 if (info->metadata_ratio)
1345 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1346 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1347 seq_puts(seq, ",fatal_errors=panic");
1348 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1349 seq_printf(seq, ",commit=%u", info->commit_interval);
1350#ifdef CONFIG_BTRFS_DEBUG
1351 if (btrfs_test_opt(info, FRAGMENT_DATA))
1352 seq_puts(seq, ",fragment=data");
1353 if (btrfs_test_opt(info, FRAGMENT_METADATA))
1354 seq_puts(seq, ",fragment=metadata");
1355#endif
1356 if (btrfs_test_opt(info, REF_VERIFY))
1357 seq_puts(seq, ",ref_verify");
1358 seq_printf(seq, ",subvolid=%llu",
1359 BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1360 seq_puts(seq, ",subvol=");
1361 seq_dentry(seq, dentry, " \t\n\\");
1362 return 0;
1363}
1364
1365static int btrfs_test_super(struct super_block *s, void *data)
1366{
1367 struct btrfs_fs_info *p = data;
1368 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1369
1370 return fs_info->fs_devices == p->fs_devices;
1371}
1372
1373static int btrfs_set_super(struct super_block *s, void *data)
1374{
1375 int err = set_anon_super(s, data);
1376 if (!err)
1377 s->s_fs_info = data;
1378 return err;
1379}
1380
1381/*
1382 * subvolumes are identified by ino 256
1383 */
1384static inline int is_subvolume_inode(struct inode *inode)
1385{
1386 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1387 return 1;
1388 return 0;
1389}
1390
1391static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1392 const char *device_name, struct vfsmount *mnt)
1393{
1394 struct dentry *root;
1395 int ret;
1396
1397 if (!subvol_name) {
1398 if (!subvol_objectid) {
1399 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1400 &subvol_objectid);
1401 if (ret) {
1402 root = ERR_PTR(ret);
1403 goto out;
1404 }
1405 }
1406 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
1407 subvol_objectid);
1408 if (IS_ERR(subvol_name)) {
1409 root = ERR_CAST(subvol_name);
1410 subvol_name = NULL;
1411 goto out;
1412 }
1413
1414 }
1415
1416 root = mount_subtree(mnt, subvol_name);
1417 /* mount_subtree() drops our reference on the vfsmount. */
1418 mnt = NULL;
1419
1420 if (!IS_ERR(root)) {
1421 struct super_block *s = root->d_sb;
1422 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1423 struct inode *root_inode = d_inode(root);
1424 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1425
1426 ret = 0;
1427 if (!is_subvolume_inode(root_inode)) {
1428 btrfs_err(fs_info, "'%s' is not a valid subvolume",
1429 subvol_name);
1430 ret = -EINVAL;
1431 }
1432 if (subvol_objectid && root_objectid != subvol_objectid) {
1433 /*
1434 * This will also catch a race condition where a
1435 * subvolume which was passed by ID is renamed and
1436 * another subvolume is renamed over the old location.
1437 */
1438 btrfs_err(fs_info,
1439 "subvol '%s' does not match subvolid %llu",
1440 subvol_name, subvol_objectid);
1441 ret = -EINVAL;
1442 }
1443 if (ret) {
1444 dput(root);
1445 root = ERR_PTR(ret);
1446 deactivate_locked_super(s);
1447 }
1448 }
1449
1450out:
1451 mntput(mnt);
1452 kfree(subvol_name);
1453 return root;
1454}
1455
1456static int parse_security_options(char *orig_opts,
1457 struct security_mnt_opts *sec_opts)
1458{
1459 char *secdata = NULL;
1460 int ret = 0;
1461
1462 secdata = alloc_secdata();
1463 if (!secdata)
1464 return -ENOMEM;
1465 ret = security_sb_copy_data(orig_opts, secdata);
1466 if (ret) {
1467 free_secdata(secdata);
1468 return ret;
1469 }
1470 ret = security_sb_parse_opts_str(secdata, sec_opts);
1471 free_secdata(secdata);
1472 return ret;
1473}
1474
1475static int setup_security_options(struct btrfs_fs_info *fs_info,
1476 struct super_block *sb,
1477 struct security_mnt_opts *sec_opts)
1478{
1479 int ret = 0;
1480
1481 /*
1482 * Call security_sb_set_mnt_opts() to check whether new sec_opts
1483 * is valid.
1484 */
1485 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
1486 if (ret)
1487 return ret;
1488
1489#ifdef CONFIG_SECURITY
1490 if (!fs_info->security_opts.num_mnt_opts) {
1491 /* first time security setup, copy sec_opts to fs_info */
1492 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
1493 } else {
1494 /*
1495 * Since SELinux (the only one supporting security_mnt_opts)
1496 * does NOT support changing context during remount/mount of
1497 * the same sb, this must be the same or part of the same
1498 * security options, just free it.
1499 */
1500 security_free_mnt_opts(sec_opts);
1501 }
1502#endif
1503 return ret;
1504}
1505
1506/*
1507 * Find a superblock for the given device / mount point.
1508 *
1509 * Note: This is based on mount_bdev from fs/super.c with a few additions
1510 * for multiple device setup. Make sure to keep it in sync.
1511 */
1512static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1513 int flags, const char *device_name, void *data)
1514{
1515 struct block_device *bdev = NULL;
1516 struct super_block *s;
1517 struct btrfs_fs_devices *fs_devices = NULL;
1518 struct btrfs_fs_info *fs_info = NULL;
1519 struct security_mnt_opts new_sec_opts;
1520 fmode_t mode = FMODE_READ;
1521 int error = 0;
1522
1523 if (!(flags & SB_RDONLY))
1524 mode |= FMODE_WRITE;
1525
1526 error = btrfs_parse_early_options(data, mode, fs_type,
1527 &fs_devices);
1528 if (error) {
1529 return ERR_PTR(error);
1530 }
1531
1532 security_init_mnt_opts(&new_sec_opts);
1533 if (data) {
1534 error = parse_security_options(data, &new_sec_opts);
1535 if (error)
1536 return ERR_PTR(error);
1537 }
1538
1539 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1540 if (error)
1541 goto error_sec_opts;
1542
1543 /*
1544 * Setup a dummy root and fs_info for test/set super. This is because
1545 * we don't actually fill this stuff out until open_ctree, but we need
1546 * it for searching for existing supers, so this lets us do that and
1547 * then open_ctree will properly initialize everything later.
1548 */
1549 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1550 if (!fs_info) {
1551 error = -ENOMEM;
1552 goto error_sec_opts;
1553 }
1554
1555 fs_info->fs_devices = fs_devices;
1556
1557 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1558 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1559 security_init_mnt_opts(&fs_info->security_opts);
1560 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1561 error = -ENOMEM;
1562 goto error_fs_info;
1563 }
1564
1565 error = btrfs_open_devices(fs_devices, mode, fs_type);
1566 if (error)
1567 goto error_fs_info;
1568
1569 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1570 error = -EACCES;
1571 goto error_close_devices;
1572 }
1573
1574 bdev = fs_devices->latest_bdev;
1575 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1576 fs_info);
1577 if (IS_ERR(s)) {
1578 error = PTR_ERR(s);
1579 goto error_close_devices;
1580 }
1581
1582 if (s->s_root) {
1583 btrfs_close_devices(fs_devices);
1584 free_fs_info(fs_info);
1585 if ((flags ^ s->s_flags) & SB_RDONLY)
1586 error = -EBUSY;
1587 } else {
1588 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1589 btrfs_sb(s)->bdev_holder = fs_type;
1590 error = btrfs_fill_super(s, fs_devices, data);
1591 }
1592 if (error) {
1593 deactivate_locked_super(s);
1594 goto error_sec_opts;
1595 }
1596
1597 fs_info = btrfs_sb(s);
1598 error = setup_security_options(fs_info, s, &new_sec_opts);
1599 if (error) {
1600 deactivate_locked_super(s);
1601 goto error_sec_opts;
1602 }
1603
1604 return dget(s->s_root);
1605
1606error_close_devices:
1607 btrfs_close_devices(fs_devices);
1608error_fs_info:
1609 free_fs_info(fs_info);
1610error_sec_opts:
1611 security_free_mnt_opts(&new_sec_opts);
1612 return ERR_PTR(error);
1613}
1614
1615/*
1616 * Mount function which is called by VFS layer.
1617 *
1618 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1619 * which needs vfsmount* of device's root (/). This means device's root has to
1620 * be mounted internally in any case.
1621 *
1622 * Operation flow:
1623 * 1. Parse subvol id related options for later use in mount_subvol().
1624 *
1625 * 2. Mount device's root (/) by calling vfs_kern_mount().
1626 *
1627 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1628 * first place. In order to avoid calling btrfs_mount() again, we use
1629 * different file_system_type which is not registered to VFS by
1630 * register_filesystem() (btrfs_root_fs_type). As a result,
1631 * btrfs_mount_root() is called. The return value will be used by
1632 * mount_subtree() in mount_subvol().
1633 *
1634 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is
1635 * "btrfs subvolume set-default", mount_subvol() is called always.
1636 */
1637static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1638 const char *device_name, void *data)
1639{
1640 struct vfsmount *mnt_root;
1641 struct dentry *root;
1642 fmode_t mode = FMODE_READ;
1643 char *subvol_name = NULL;
1644 u64 subvol_objectid = 0;
1645 int error = 0;
1646
1647 if (!(flags & SB_RDONLY))
1648 mode |= FMODE_WRITE;
1649
1650 error = btrfs_parse_subvol_options(data, mode,
1651 &subvol_name, &subvol_objectid);
1652 if (error) {
1653 kfree(subvol_name);
1654 return ERR_PTR(error);
1655 }
1656
1657 /* mount device's root (/) */
1658 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1659 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1660 if (flags & SB_RDONLY) {
1661 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1662 flags & ~SB_RDONLY, device_name, data);
1663 } else {
1664 mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1665 flags | SB_RDONLY, device_name, data);
1666 if (IS_ERR(mnt_root)) {
1667 root = ERR_CAST(mnt_root);
1668 goto out;
1669 }
1670
1671 down_write(&mnt_root->mnt_sb->s_umount);
1672 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1673 up_write(&mnt_root->mnt_sb->s_umount);
1674 if (error < 0) {
1675 root = ERR_PTR(error);
1676 mntput(mnt_root);
1677 goto out;
1678 }
1679 }
1680 }
1681 if (IS_ERR(mnt_root)) {
1682 root = ERR_CAST(mnt_root);
1683 goto out;
1684 }
1685
1686 /* mount_subvol() will free subvol_name and mnt_root */
1687 root = mount_subvol(subvol_name, subvol_objectid, device_name, mnt_root);
1688
1689out:
1690 return root;
1691}
1692
1693static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1694 u32 new_pool_size, u32 old_pool_size)
1695{
1696 if (new_pool_size == old_pool_size)
1697 return;
1698
1699 fs_info->thread_pool_size = new_pool_size;
1700
1701 btrfs_info(fs_info, "resize thread pool %d -> %d",
1702 old_pool_size, new_pool_size);
1703
1704 btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1705 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1706 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1707 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1708 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1709 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1710 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1711 new_pool_size);
1712 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1713 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1714 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1715 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1716 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1717 new_pool_size);
1718}
1719
1720static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1721{
1722 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1723}
1724
1725static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1726 unsigned long old_opts, int flags)
1727{
1728 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1729 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1730 (flags & SB_RDONLY))) {
1731 /* wait for any defraggers to finish */
1732 wait_event(fs_info->transaction_wait,
1733 (atomic_read(&fs_info->defrag_running) == 0));
1734 if (flags & SB_RDONLY)
1735 sync_filesystem(fs_info->sb);
1736 }
1737}
1738
1739static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1740 unsigned long old_opts)
1741{
1742 /*
1743 * We need to cleanup all defragable inodes if the autodefragment is
1744 * close or the filesystem is read only.
1745 */
1746 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1747 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1748 btrfs_cleanup_defrag_inodes(fs_info);
1749 }
1750
1751 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1752}
1753
1754static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1755{
1756 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1757 struct btrfs_root *root = fs_info->tree_root;
1758 unsigned old_flags = sb->s_flags;
1759 unsigned long old_opts = fs_info->mount_opt;
1760 unsigned long old_compress_type = fs_info->compress_type;
1761 u64 old_max_inline = fs_info->max_inline;
1762 u32 old_thread_pool_size = fs_info->thread_pool_size;
1763 u32 old_metadata_ratio = fs_info->metadata_ratio;
1764 int ret;
1765
1766 sync_filesystem(sb);
1767 btrfs_remount_prepare(fs_info);
1768
1769 if (data) {
1770 struct security_mnt_opts new_sec_opts;
1771
1772 security_init_mnt_opts(&new_sec_opts);
1773 ret = parse_security_options(data, &new_sec_opts);
1774 if (ret)
1775 goto restore;
1776 ret = setup_security_options(fs_info, sb,
1777 &new_sec_opts);
1778 if (ret) {
1779 security_free_mnt_opts(&new_sec_opts);
1780 goto restore;
1781 }
1782 }
1783
1784 ret = btrfs_parse_options(fs_info, data, *flags);
1785 if (ret) {
1786 ret = -EINVAL;
1787 goto restore;
1788 }
1789
1790 btrfs_remount_begin(fs_info, old_opts, *flags);
1791 btrfs_resize_thread_pool(fs_info,
1792 fs_info->thread_pool_size, old_thread_pool_size);
1793
1794 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1795 goto out;
1796
1797 if (*flags & SB_RDONLY) {
1798 /*
1799 * this also happens on 'umount -rf' or on shutdown, when
1800 * the filesystem is busy.
1801 */
1802 cancel_work_sync(&fs_info->async_reclaim_work);
1803
1804 /* wait for the uuid_scan task to finish */
1805 down(&fs_info->uuid_tree_rescan_sem);
1806 /* avoid complains from lockdep et al. */
1807 up(&fs_info->uuid_tree_rescan_sem);
1808
1809 sb->s_flags |= SB_RDONLY;
1810
1811 /*
1812 * Setting SB_RDONLY will put the cleaner thread to
1813 * sleep at the next loop if it's already active.
1814 * If it's already asleep, we'll leave unused block
1815 * groups on disk until we're mounted read-write again
1816 * unless we clean them up here.
1817 */
1818 btrfs_delete_unused_bgs(fs_info);
1819
1820 btrfs_dev_replace_suspend_for_unmount(fs_info);
1821 btrfs_scrub_cancel(fs_info);
1822 btrfs_pause_balance(fs_info);
1823
1824 ret = btrfs_commit_super(fs_info);
1825 if (ret)
1826 goto restore;
1827 } else {
1828 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1829 btrfs_err(fs_info,
1830 "Remounting read-write after error is not allowed");
1831 ret = -EINVAL;
1832 goto restore;
1833 }
1834 if (fs_info->fs_devices->rw_devices == 0) {
1835 ret = -EACCES;
1836 goto restore;
1837 }
1838
1839 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
1840 btrfs_warn(fs_info,
1841 "too many missing devices, writeable remount is not allowed");
1842 ret = -EACCES;
1843 goto restore;
1844 }
1845
1846 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1847 ret = -EINVAL;
1848 goto restore;
1849 }
1850
1851 ret = btrfs_cleanup_fs_roots(fs_info);
1852 if (ret)
1853 goto restore;
1854
1855 /* recover relocation */
1856 mutex_lock(&fs_info->cleaner_mutex);
1857 ret = btrfs_recover_relocation(root);
1858 mutex_unlock(&fs_info->cleaner_mutex);
1859 if (ret)
1860 goto restore;
1861
1862 ret = btrfs_resume_balance_async(fs_info);
1863 if (ret)
1864 goto restore;
1865
1866 ret = btrfs_resume_dev_replace_async(fs_info);
1867 if (ret) {
1868 btrfs_warn(fs_info, "failed to resume dev_replace");
1869 goto restore;
1870 }
1871
1872 btrfs_qgroup_rescan_resume(fs_info);
1873
1874 if (!fs_info->uuid_root) {
1875 btrfs_info(fs_info, "creating UUID tree");
1876 ret = btrfs_create_uuid_tree(fs_info);
1877 if (ret) {
1878 btrfs_warn(fs_info,
1879 "failed to create the UUID tree %d",
1880 ret);
1881 goto restore;
1882 }
1883 }
1884 sb->s_flags &= ~SB_RDONLY;
1885
1886 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1887 }
1888out:
1889 wake_up_process(fs_info->transaction_kthread);
1890 btrfs_remount_cleanup(fs_info, old_opts);
1891 return 0;
1892
1893restore:
1894 /* We've hit an error - don't reset SB_RDONLY */
1895 if (sb_rdonly(sb))
1896 old_flags |= SB_RDONLY;
1897 sb->s_flags = old_flags;
1898 fs_info->mount_opt = old_opts;
1899 fs_info->compress_type = old_compress_type;
1900 fs_info->max_inline = old_max_inline;
1901 btrfs_resize_thread_pool(fs_info,
1902 old_thread_pool_size, fs_info->thread_pool_size);
1903 fs_info->metadata_ratio = old_metadata_ratio;
1904 btrfs_remount_cleanup(fs_info, old_opts);
1905 return ret;
1906}
1907
1908/* Used to sort the devices by max_avail(descending sort) */
1909static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1910 const void *dev_info2)
1911{
1912 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1913 ((struct btrfs_device_info *)dev_info2)->max_avail)
1914 return -1;
1915 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1916 ((struct btrfs_device_info *)dev_info2)->max_avail)
1917 return 1;
1918 else
1919 return 0;
1920}
1921
1922/*
1923 * sort the devices by max_avail, in which max free extent size of each device
1924 * is stored.(Descending Sort)
1925 */
1926static inline void btrfs_descending_sort_devices(
1927 struct btrfs_device_info *devices,
1928 size_t nr_devices)
1929{
1930 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1931 btrfs_cmp_device_free_bytes, NULL);
1932}
1933
1934/*
1935 * The helper to calc the free space on the devices that can be used to store
1936 * file data.
1937 */
1938static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1939 u64 *free_bytes)
1940{
1941 struct btrfs_device_info *devices_info;
1942 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1943 struct btrfs_device *device;
1944 u64 skip_space;
1945 u64 type;
1946 u64 avail_space;
1947 u64 min_stripe_size;
1948 int min_stripes = 1, num_stripes = 1;
1949 int i = 0, nr_devices;
1950
1951 /*
1952 * We aren't under the device list lock, so this is racy-ish, but good
1953 * enough for our purposes.
1954 */
1955 nr_devices = fs_info->fs_devices->open_devices;
1956 if (!nr_devices) {
1957 smp_mb();
1958 nr_devices = fs_info->fs_devices->open_devices;
1959 ASSERT(nr_devices);
1960 if (!nr_devices) {
1961 *free_bytes = 0;
1962 return 0;
1963 }
1964 }
1965
1966 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1967 GFP_KERNEL);
1968 if (!devices_info)
1969 return -ENOMEM;
1970
1971 /* calc min stripe number for data space allocation */
1972 type = btrfs_data_alloc_profile(fs_info);
1973 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1974 min_stripes = 2;
1975 num_stripes = nr_devices;
1976 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1977 min_stripes = 2;
1978 num_stripes = 2;
1979 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1980 min_stripes = 4;
1981 num_stripes = 4;
1982 }
1983
1984 if (type & BTRFS_BLOCK_GROUP_DUP)
1985 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1986 else
1987 min_stripe_size = BTRFS_STRIPE_LEN;
1988
1989 rcu_read_lock();
1990 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1991 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
1992 &device->dev_state) ||
1993 !device->bdev ||
1994 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
1995 continue;
1996
1997 if (i >= nr_devices)
1998 break;
1999
2000 avail_space = device->total_bytes - device->bytes_used;
2001
2002 /* align with stripe_len */
2003 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
2004 avail_space *= BTRFS_STRIPE_LEN;
2005
2006 /*
2007 * In order to avoid overwriting the superblock on the drive,
2008 * btrfs starts at an offset of at least 1MB when doing chunk
2009 * allocation.
2010 */
2011 skip_space = SZ_1M;
2012
2013 /*
2014 * we can use the free space in [0, skip_space - 1], subtract
2015 * it from the total.
2016 */
2017 if (avail_space && avail_space >= skip_space)
2018 avail_space -= skip_space;
2019 else
2020 avail_space = 0;
2021
2022 if (avail_space < min_stripe_size)
2023 continue;
2024
2025 devices_info[i].dev = device;
2026 devices_info[i].max_avail = avail_space;
2027
2028 i++;
2029 }
2030 rcu_read_unlock();
2031
2032 nr_devices = i;
2033
2034 btrfs_descending_sort_devices(devices_info, nr_devices);
2035
2036 i = nr_devices - 1;
2037 avail_space = 0;
2038 while (nr_devices >= min_stripes) {
2039 if (num_stripes > nr_devices)
2040 num_stripes = nr_devices;
2041
2042 if (devices_info[i].max_avail >= min_stripe_size) {
2043 int j;
2044 u64 alloc_size;
2045
2046 avail_space += devices_info[i].max_avail * num_stripes;
2047 alloc_size = devices_info[i].max_avail;
2048 for (j = i + 1 - num_stripes; j <= i; j++)
2049 devices_info[j].max_avail -= alloc_size;
2050 }
2051 i--;
2052 nr_devices--;
2053 }
2054
2055 kfree(devices_info);
2056 *free_bytes = avail_space;
2057 return 0;
2058}
2059
2060/*
2061 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
2062 *
2063 * If there's a redundant raid level at DATA block groups, use the respective
2064 * multiplier to scale the sizes.
2065 *
2066 * Unused device space usage is based on simulating the chunk allocator
2067 * algorithm that respects the device sizes and order of allocations. This is
2068 * a close approximation of the actual use but there are other factors that may
2069 * change the result (like a new metadata chunk).
2070 *
2071 * If metadata is exhausted, f_bavail will be 0.
2072 */
2073static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
2074{
2075 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
2076 struct btrfs_super_block *disk_super = fs_info->super_copy;
2077 struct list_head *head = &fs_info->space_info;
2078 struct btrfs_space_info *found;
2079 u64 total_used = 0;
2080 u64 total_free_data = 0;
2081 u64 total_free_meta = 0;
2082 int bits = dentry->d_sb->s_blocksize_bits;
2083 __be32 *fsid = (__be32 *)fs_info->fsid;
2084 unsigned factor = 1;
2085 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
2086 int ret;
2087 u64 thresh = 0;
2088 int mixed = 0;
2089
2090 rcu_read_lock();
2091 list_for_each_entry_rcu(found, head, list) {
2092 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2093 int i;
2094
2095 total_free_data += found->disk_total - found->disk_used;
2096 total_free_data -=
2097 btrfs_account_ro_block_groups_free_space(found);
2098
2099 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2100 if (!list_empty(&found->block_groups[i])) {
2101 switch (i) {
2102 case BTRFS_RAID_DUP:
2103 case BTRFS_RAID_RAID1:
2104 case BTRFS_RAID_RAID10:
2105 factor = 2;
2106 }
2107 }
2108 }
2109 }
2110
2111 /*
2112 * Metadata in mixed block goup profiles are accounted in data
2113 */
2114 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2115 if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2116 mixed = 1;
2117 else
2118 total_free_meta += found->disk_total -
2119 found->disk_used;
2120 }
2121
2122 total_used += found->disk_used;
2123 }
2124
2125 rcu_read_unlock();
2126
2127 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2128 buf->f_blocks >>= bits;
2129 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2130
2131 /* Account global block reserve as used, it's in logical size already */
2132 spin_lock(&block_rsv->lock);
2133 /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2134 if (buf->f_bfree >= block_rsv->size >> bits)
2135 buf->f_bfree -= block_rsv->size >> bits;
2136 else
2137 buf->f_bfree = 0;
2138 spin_unlock(&block_rsv->lock);
2139
2140 buf->f_bavail = div_u64(total_free_data, factor);
2141 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2142 if (ret)
2143 return ret;
2144 buf->f_bavail += div_u64(total_free_data, factor);
2145 buf->f_bavail = buf->f_bavail >> bits;
2146
2147 /*
2148 * We calculate the remaining metadata space minus global reserve. If
2149 * this is (supposedly) smaller than zero, there's no space. But this
2150 * does not hold in practice, the exhausted state happens where's still
2151 * some positive delta. So we apply some guesswork and compare the
2152 * delta to a 4M threshold. (Practically observed delta was ~2M.)
2153 *
2154 * We probably cannot calculate the exact threshold value because this
2155 * depends on the internal reservations requested by various
2156 * operations, so some operations that consume a few metadata will
2157 * succeed even if the Avail is zero. But this is better than the other
2158 * way around.
2159 */
2160 thresh = SZ_4M;
2161
2162 if (!mixed && total_free_meta - thresh < block_rsv->size)
2163 buf->f_bavail = 0;
2164
2165 buf->f_type = BTRFS_SUPER_MAGIC;
2166 buf->f_bsize = dentry->d_sb->s_blocksize;
2167 buf->f_namelen = BTRFS_NAME_LEN;
2168
2169 /* We treat it as constant endianness (it doesn't matter _which_)
2170 because we want the fsid to come out the same whether mounted
2171 on a big-endian or little-endian host */
2172 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2173 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2174 /* Mask in the root object ID too, to disambiguate subvols */
2175 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32;
2176 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid;
2177
2178 return 0;
2179}
2180
2181static void btrfs_kill_super(struct super_block *sb)
2182{
2183 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2184 kill_anon_super(sb);
2185 free_fs_info(fs_info);
2186}
2187
2188static struct file_system_type btrfs_fs_type = {
2189 .owner = THIS_MODULE,
2190 .name = "btrfs",
2191 .mount = btrfs_mount,
2192 .kill_sb = btrfs_kill_super,
2193 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2194};
2195
2196static struct file_system_type btrfs_root_fs_type = {
2197 .owner = THIS_MODULE,
2198 .name = "btrfs",
2199 .mount = btrfs_mount_root,
2200 .kill_sb = btrfs_kill_super,
2201 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2202};
2203
2204MODULE_ALIAS_FS("btrfs");
2205
2206static int btrfs_control_open(struct inode *inode, struct file *file)
2207{
2208 /*
2209 * The control file's private_data is used to hold the
2210 * transaction when it is started and is used to keep
2211 * track of whether a transaction is already in progress.
2212 */
2213 file->private_data = NULL;
2214 return 0;
2215}
2216
2217/*
2218 * used by btrfsctl to scan devices when no FS is mounted
2219 */
2220static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2221 unsigned long arg)
2222{
2223 struct btrfs_ioctl_vol_args *vol;
2224 struct btrfs_fs_devices *fs_devices;
2225 int ret = -ENOTTY;
2226
2227 if (!capable(CAP_SYS_ADMIN))
2228 return -EPERM;
2229
2230 vol = memdup_user((void __user *)arg, sizeof(*vol));
2231 if (IS_ERR(vol))
2232 return PTR_ERR(vol);
2233
2234 switch (cmd) {
2235 case BTRFS_IOC_SCAN_DEV:
2236 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2237 &btrfs_root_fs_type, &fs_devices);
2238 break;
2239 case BTRFS_IOC_DEVICES_READY:
2240 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
2241 &btrfs_root_fs_type, &fs_devices);
2242 if (ret)
2243 break;
2244 ret = !(fs_devices->num_devices == fs_devices->total_devices);
2245 break;
2246 case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2247 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2248 break;
2249 }
2250
2251 kfree(vol);
2252 return ret;
2253}
2254
2255static int btrfs_freeze(struct super_block *sb)
2256{
2257 struct btrfs_trans_handle *trans;
2258 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2259 struct btrfs_root *root = fs_info->tree_root;
2260
2261 set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2262 /*
2263 * We don't need a barrier here, we'll wait for any transaction that
2264 * could be in progress on other threads (and do delayed iputs that
2265 * we want to avoid on a frozen filesystem), or do the commit
2266 * ourselves.
2267 */
2268 trans = btrfs_attach_transaction_barrier(root);
2269 if (IS_ERR(trans)) {
2270 /* no transaction, don't bother */
2271 if (PTR_ERR(trans) == -ENOENT)
2272 return 0;
2273 return PTR_ERR(trans);
2274 }
2275 return btrfs_commit_transaction(trans);
2276}
2277
2278static int btrfs_unfreeze(struct super_block *sb)
2279{
2280 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2281
2282 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2283 return 0;
2284}
2285
2286static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2287{
2288 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2289 struct btrfs_fs_devices *cur_devices;
2290 struct btrfs_device *dev, *first_dev = NULL;
2291 struct list_head *head;
2292 struct rcu_string *name;
2293
2294 /*
2295 * Lightweight locking of the devices. We should not need
2296 * device_list_mutex here as we only read the device data and the list
2297 * is protected by RCU. Even if a device is deleted during the list
2298 * traversals, we'll get valid data, the freeing callback will wait at
2299 * least until until the rcu_read_unlock.
2300 */
2301 rcu_read_lock();
2302 cur_devices = fs_info->fs_devices;
2303 while (cur_devices) {
2304 head = &cur_devices->devices;
2305 list_for_each_entry_rcu(dev, head, dev_list) {
2306 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
2307 continue;
2308 if (!dev->name)
2309 continue;
2310 if (!first_dev || dev->devid < first_dev->devid)
2311 first_dev = dev;
2312 }
2313 cur_devices = cur_devices->seed;
2314 }
2315
2316 if (first_dev) {
2317 name = rcu_dereference(first_dev->name);
2318 seq_escape(m, name->str, " \t\n\\");
2319 } else {
2320 WARN_ON(1);
2321 }
2322 rcu_read_unlock();
2323 return 0;
2324}
2325
2326static const struct super_operations btrfs_super_ops = {
2327 .drop_inode = btrfs_drop_inode,
2328 .evict_inode = btrfs_evict_inode,
2329 .put_super = btrfs_put_super,
2330 .sync_fs = btrfs_sync_fs,
2331 .show_options = btrfs_show_options,
2332 .show_devname = btrfs_show_devname,
2333 .write_inode = btrfs_write_inode,
2334 .alloc_inode = btrfs_alloc_inode,
2335 .destroy_inode = btrfs_destroy_inode,
2336 .statfs = btrfs_statfs,
2337 .remount_fs = btrfs_remount,
2338 .freeze_fs = btrfs_freeze,
2339 .unfreeze_fs = btrfs_unfreeze,
2340};
2341
2342static const struct file_operations btrfs_ctl_fops = {
2343 .open = btrfs_control_open,
2344 .unlocked_ioctl = btrfs_control_ioctl,
2345 .compat_ioctl = btrfs_control_ioctl,
2346 .owner = THIS_MODULE,
2347 .llseek = noop_llseek,
2348};
2349
2350static struct miscdevice btrfs_misc = {
2351 .minor = BTRFS_MINOR,
2352 .name = "btrfs-control",
2353 .fops = &btrfs_ctl_fops
2354};
2355
2356MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2357MODULE_ALIAS("devname:btrfs-control");
2358
2359static int __init btrfs_interface_init(void)
2360{
2361 return misc_register(&btrfs_misc);
2362}
2363
2364static __cold void btrfs_interface_exit(void)
2365{
2366 misc_deregister(&btrfs_misc);
2367}
2368
2369static void __init btrfs_print_mod_info(void)
2370{
2371 pr_info("Btrfs loaded, crc32c=%s"
2372#ifdef CONFIG_BTRFS_DEBUG
2373 ", debug=on"
2374#endif
2375#ifdef CONFIG_BTRFS_ASSERT
2376 ", assert=on"
2377#endif
2378#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2379 ", integrity-checker=on"
2380#endif
2381#ifdef CONFIG_BTRFS_FS_REF_VERIFY
2382 ", ref-verify=on"
2383#endif
2384 "\n",
2385 crc32c_impl());
2386}
2387
2388static int __init init_btrfs_fs(void)
2389{
2390 int err;
2391
2392 btrfs_props_init();
2393
2394 err = btrfs_init_sysfs();
2395 if (err)
2396 return err;
2397
2398 btrfs_init_compress();
2399
2400 err = btrfs_init_cachep();
2401 if (err)
2402 goto free_compress;
2403
2404 err = extent_io_init();
2405 if (err)
2406 goto free_cachep;
2407
2408 err = extent_map_init();
2409 if (err)
2410 goto free_extent_io;
2411
2412 err = ordered_data_init();
2413 if (err)
2414 goto free_extent_map;
2415
2416 err = btrfs_delayed_inode_init();
2417 if (err)
2418 goto free_ordered_data;
2419
2420 err = btrfs_auto_defrag_init();
2421 if (err)
2422 goto free_delayed_inode;
2423
2424 err = btrfs_delayed_ref_init();
2425 if (err)
2426 goto free_auto_defrag;
2427
2428 err = btrfs_prelim_ref_init();
2429 if (err)
2430 goto free_delayed_ref;
2431
2432 err = btrfs_end_io_wq_init();
2433 if (err)
2434 goto free_prelim_ref;
2435
2436 err = btrfs_interface_init();
2437 if (err)
2438 goto free_end_io_wq;
2439
2440 btrfs_init_lockdep();
2441
2442 btrfs_print_mod_info();
2443
2444 err = btrfs_run_sanity_tests();
2445 if (err)
2446 goto unregister_ioctl;
2447
2448 err = register_filesystem(&btrfs_fs_type);
2449 if (err)
2450 goto unregister_ioctl;
2451
2452 return 0;
2453
2454unregister_ioctl:
2455 btrfs_interface_exit();
2456free_end_io_wq:
2457 btrfs_end_io_wq_exit();
2458free_prelim_ref:
2459 btrfs_prelim_ref_exit();
2460free_delayed_ref:
2461 btrfs_delayed_ref_exit();
2462free_auto_defrag:
2463 btrfs_auto_defrag_exit();
2464free_delayed_inode:
2465 btrfs_delayed_inode_exit();
2466free_ordered_data:
2467 ordered_data_exit();
2468free_extent_map:
2469 extent_map_exit();
2470free_extent_io:
2471 extent_io_exit();
2472free_cachep:
2473 btrfs_destroy_cachep();
2474free_compress:
2475 btrfs_exit_compress();
2476 btrfs_exit_sysfs();
2477
2478 return err;
2479}
2480
2481static void __exit exit_btrfs_fs(void)
2482{
2483 btrfs_destroy_cachep();
2484 btrfs_delayed_ref_exit();
2485 btrfs_auto_defrag_exit();
2486 btrfs_delayed_inode_exit();
2487 btrfs_prelim_ref_exit();
2488 ordered_data_exit();
2489 extent_map_exit();
2490 extent_io_exit();
2491 btrfs_interface_exit();
2492 btrfs_end_io_wq_exit();
2493 unregister_filesystem(&btrfs_fs_type);
2494 btrfs_exit_sysfs();
2495 btrfs_cleanup_fs_uuids();
2496 btrfs_exit_compress();
2497}
2498
2499late_initcall(init_btrfs_fs);
2500module_exit(exit_btrfs_fs)
2501
2502MODULE_LICENSE("GPL");